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SG24-4935-00
Unleashing AS/400 Applications on the Internet
June 1997
IBML
International Technical Support Organization
Unleashing AS/400 Applications on the Internet
June 1997
SG24-4935-00
Take Note!
Before using this information and the product it supports, be sure to read the general information in
Appendix C, “Special Notices” on page 275.
First Edition (June 1997)
This edition applies to Version 3 Release 2 and Version 3 Release 7 of the Operating System/400 (5763-SS1) and
(5716-SS1).
Comments may be addressed to:
IBM Corporation, International Technical Support Organization
Dept. JLU Building 107-2
3605 Highway 52N
Rochester, Minnesota 55901-7829
When you send information to IBM, you grant IBM a non-exclusive right to use or distribute the information in any
way it believes appropriate without incurring any obligation to you.
 Copyright International Business Machines Corporation 1997. All rights reserved.
Note to U.S. Government Users — Documentation related to restricted rights — Use, duplication or disclosure is
subject to restrictions set forth in GSA ADP Schedule Contract with IBM Corp.
Contents
Figures
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Tables
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Preface
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The Team That Wrote This Redbook
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Comments Welcome
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Chapter 1. AS/400  System in Network Computing Environment
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1.1 What is the Internet
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1.2 History of Internet
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1.3 Network Computing
1.4 Why Attach an AS/400 System to the Internet? . . . . . . . .
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Chapter 2. Internet Application Design Considerations . . . . . . .
2.1.1 Network-Centric Computing . . . . . . . . . . . . . . . . . .
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2.2 AS/400 Internet Application Scenarios
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2.3 Different Web Models
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2.3.1 Simple Web Model
2.3.2 Interactive Web Model . . . . . . . . . . . . . . . . . . . . .
2.3.3 Distributed Web Model . . . . . . . . . . . . . . . . . . . . .
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2.3.4 Enterprise Distributed Web Model
2.4 AS/400 System Facilities for the Internet . . . . . . . . . . . . .
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2.4.1 Database Services
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2.4.2 Application Access
2.4.3 Content Authoring . . . . . . . . . . . . . . . . . . . . . . . .
2.4.4 Content Management . . . . . . . . . . . . . . . . . . . . . .
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2.4.5 Java Development Environment
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2.5 General Design Considerations
2.5.1 Transactions over the World Wide Web using the Internet
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2.5.2 Synchronization between Web Browser and Server
2.5.3 End User Driven . . . . . . . . . . . . . . . . . . . . . . . . .
2.5.4 End User Anonymous . . . . . . . . . . . . . . . . . . . . . .
2.5.5 Status of User Requests . . . . . . . . . . . . . . . . . . . .
2.5.6 National Characters, Code Pages, Date Format . . . . . .
2.5.7 Internet - Intranet - Extranet Considerations . . . . . . . .
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2.5.8 Internet Application Error Recovery
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2.6 Programming Alternatives
2.7 Internet Programming Models . . . . . . . . . . . . . . . . . . .
2.7.1 HTTP CGI Programming Model . . . . . . . . . . . . . . . .
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2.7.2 Java Applet Communicating to CGI
2.7.3 Net.Data Macros . . . . . . . . . . . . . . . . . . . . . . . . .
2.7.4 The Internet Client/Server Programming Model . . . . . .
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2.7.5 Lotus Domino
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2.8 Supporting the AS/400 Legacy Programming Models
2.8.1 The 5250 Workstation Gateway . . . . . . . . . . . . . . . .
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2.8.2 ″On-the-Fly″ Translation versus the Toolkit Approach
2.8.3 Telnet and Client Access  - Personal Communication . .
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2.9 HTML Programming Considerations
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2.9.1 Hypertext Markup Language (HTML)
2.9.2 The HTML Document Structure . . . . . . . . . . . . . . . .
 Copyright IBM Corp. 1997
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2.9.3 HTML Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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2.9.4 Creating Static HTML Pages
2.9.5 Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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2.10 Server Side Imagemap Support
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2.10.2 Server Side Image Maps Considerations
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2.11 Netscape, Microsoft  IE, IBM Web Explorer, Spyglass
2.12 ILE Integrated Language Environment  Programming Considerations
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2.12.1 Overview of ILE Concepts
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2.12.2 ILE Compile and Bind Commands
2.12.3 OPM Compatibility Mode . . . . . . . . . . . . . . . . . . . . . . . . .
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2.12.4 Activation Groups
2.12.5 Activation Group Recommendations . . . . . . . . . . . . . . . . . .
2.12.6 Differences Between Default and Non-Default Activation Groups .
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2.12.7 Migration to ILE from the Original Programming Model
2.13 IFS - Integrated File System Considerations . . . . . . . . . . . . . . . .
2.13.1 Short Overview of Various File Systems in IFS . . . . . . . . . . . .
2.13.2 Which AS/400 File System Works Best? . . . . . . . . . . . . . . . .
2.13.3 How to Exchange Data Between the Root or QOpenSys and
QSYS.LIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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2.14 Java Programming Considerations
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2.14.1 Java Scripts being Served from AS/400 System
2.14.2 Java Applets being Served from AS/400 System . . . . . . . . . . .
2.14.3 Java Applications being Executed on AS/400 Java Virtual Machine
2.14.4 Using NetRexx to Create Java Applets . . . . . . . . . . . . . . . . .
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2.14.5 Using Perl to Create Java Applets
2.14.6 Using VisualAge for Java to Create Applets and Applications . . .
2.15 Application Security Considerations . . . . . . . . . . . . . . . . . . . . .
2.15.1 Related Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.16 Internet URL References for More Information . . . . . . . . . . . . . . .
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2.17 Road Map for Internet Application Design
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation . . . .
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3.1 HTTP CGI Programming Model
3.2 Considerations Before You Start . . . . . . . . . . . . . . . . . . . . . .
3.2.1 Required Configuration . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.2 Overview of the Communication Between CGI Programs and the
Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 CGI-BIN Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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3.3.1 HTML Form Tags
3.4 GET Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5 POST Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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3.6 AS/400 Programming Languages Supported
3.7 Decoding the Parameters from the Remote Web Client . . . . . . . .
3.7.1 CGI Parameter String Syntax . . . . . . . . . . . . . . . . . . . . .
3.8 Programming CGI-BIN with ILE C/400 . . . . . . . . . . . . . . . . . . .
3.8.1 Structure of C Program with POST Method . . . . . . . . . . . . .
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3.8.2 CGI Parameter Parsing with ILE C/400
3.8.3 ILE C Sample Programs using POST and GET Methods . . . . .
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3.9 Programming CGI-BIN with ILE RPG/400 and ILE COBOL/400
3.9.1 Structure of RPG Program Using POST Method . . . . . . . . . .
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3.9.2 CGI Parameter Parsing with ILE COBOL/400 or RPG/400
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3.9.3 ILE RPG Program Using the POST and GET Methods
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3.10 Programming CGI with REXX Language
3.10.1 Structure of REXX Program Using POST Method . . . . . . . . .
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3.11 Examples for Environment Variables
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3.12.1 Source Code RPG Program ORDAS400G
3.12.2 Source Code RPG Program ORDAS400P
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Chapter 4. Net.Data Implementation . . . . . . . . . . . . .
4.1 An Overview of Net.Data for AS/400 System . . . . . .
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4.1.1 Beyond DB2WWW Connection
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4.1.2 Features and Functions
4.1.3 Generalized Data Sources . . . . . . . . . . . . . .
4.1.4 Advanced Macro Language . . . . . . . . . . . . .
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4.1.5 Net.Data and Internet Security
4.2 Writing Net.Data Macro Files . . . . . . . . . . . . . . .
4.2.1 Define Section . . . . . . . . . . . . . . . . . . . . .
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4.2.2 Function Definition Section
4.2.3 HTML INPUT Section . . . . . . . . . . . . . . . . .
4.2.4 HTML OUTPUT Section . . . . . . . . . . . . . . . .
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4.3 Generating HTML in a Web Macro
4.3.1 HTML Blocks . . . . . . . . . . . . . . . . . . . . . .
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4.4 Web Macro Functions
4.4.1 Define Functions . . . . . . . . . . . . . . . . . . . .
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4.4.2 Calling Functions
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4.4.3 Net.Data Built-In Functions
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4.4.4 Table Variables
4.4.5 Implicitly Defined Variables . . . . . . . . . . . . .
4.5 Report Blocks . . . . . . . . . . . . . . . . . . . . . . . .
4.5.1 Message Blocks . . . . . . . . . . . . . . . . . . . .
4.6 Language Environments . . . . . . . . . . . . . . . . . .
4.6.1 REXX (DTW_REXX) Language Environment . . . .
4.6.2 SQL (DTW_SQL or SQL) Language Environment
4.6.3 SYSTEM (DTW_SYSTEM) Language Environment
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4.7 Net.Data Advanced Macro Language Examples
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4.7.1 Multiple HTML Sections
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4.7.2 Using Include Files
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4.7.3 Conditional Logic
4.7.4 Maintaining State using ″HTML″ Hidden Variables
4.7.5 Net.Data Hidden Variables . . . . . . . . . . . . . .
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4.7.6 Net.Data Predefined Variables
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4.7.7 Net.Data Environment Variables
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4.7.8 Net.Data Default Report
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4.8 Additional Tips
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4.8.1 Net.Data Error Messages
4.9 Getting Net.Data Up and Running . . . . . . . . . . . .
4.9.1 Example URL Calling Net.Data Macro . . . . . . .
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4.10 Migrating from DB2 WWW Connection to Net.Data
4.11 Debug HTTP Server Setup for Net.Data . . . . . . . .
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4.12 Service and Support
Chapter 5. HTML Gateway Implementation . . . . . . . . .
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5.1 What is an HTML Gateway?
5.2 Using the HTML Gateway in Application Development
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5.3 IBM Workstation Gateway (WSG)
5.3.1 Getting Started . . . . . . . . . . . . . . . . . . . . .
5.3.2 Workstation Gateway Server Jobs . . . . . . . . .
5.3.3 Using Workstation Gateway . . . . . . . . . . . . .
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5.4 Application Development with Workstation Gateway
5.4.1 Existing Applications (Display Files) . . . . . .
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5.4.2 DDS to HTML Conversion
5.4.3 DDS HTML Support . . . . . . . . . . . . . . . .
5.4.4 Logon Exit Programs . . . . . . . . . . . . . . .
5.5 Tips for using Workstation Gateway . . . . . . . . .
5.6 I/NET′ s Webulator/400 . . . . . . . . . . . . . . . . .
5.6.1 Getting Started . . . . . . . . . . . . . . . . . . .
5.6.2 Webulator/400 Sign-On Methods . . . . . . . .
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5.6.3 Using Webulator/400
5.7 Application Development with Webulator/400 . . .
5.7.1 Signing Off . . . . . . . . . . . . . . . . . . . . .
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5.7.2 Existing Applications
5.7.3 DDS HTML Support . . . . . . . . . . . . . . . .
5.7.4 Additional Customization of Webulator/400 . .
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5.8 Hints for Using Webulator/400
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5.9 Other Implementation Tips
5.10 HTML Gateway Comparison . . . . . . . . . . . . .
5.11 Further Information . . . . . . . . . . . . . . . . . .
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5.11.1 Workstation Gateway
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5.11.2 Webulator/400
5.11.3 Additional Publications on the Web . . . . . .
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5.12 HTML Gateway versus Other Methods
5.13 Future Developments . . . . . . . . . . . . . . . . .
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5.13.1 Workstation Gateway
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5.13.2 Webulator/400
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5.14 Conclusions
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Chapter 6. Further Enhancing Your AS/400 HTML Pages
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6.1 Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.1.1 Java Applets . . . . . . . . . . . . . . . . . . . . . . . . .
6.1.2 Java Applications . . . . . . . . . . . . . . . . . . . . . .
6.1.3 How Do I Serve Java Applets from the AS/400 System
6.2 JavaScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.1 What is JavaScript? . . . . . . . . . . . . . . . . . . . . .
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6.2.2 Webulator/400 and JavaScript
6.2.3 Why Disable JavaScript? . . . . . . . . . . . . . . . . . .
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6.3 Further Java/JavaScript Information
Chapter 7. AS/400 Internet Technology Preview . . .
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7.1 AS/400 Firewall Technology
7.1.1 AS/400 Firewall Benefits . . . . . . . . . . . .
7.1.2 The AS/400 Advantage . . . . . . . . . . . . .
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7.1.3 AS/400 Technology Advantages
7.1.4 AS/400 Firewall Technology Components . .
7.2 Internet Connection Secure Server/400 (ICSS/400)
7.3 New Versions of HTTP . . . . . . . . . . . . . . . .
7.4 IBM Electronic Commerce - Net.Commerce . . .
7.4.1 What Does Net.Commerce Do? . . . . . . . .
7.4.2 Construct a Site for Your Business . . . . . .
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7.4.3 Create a Dynamic Shopping Experience
7.4.4 Manage the Shopping Process End-to-End .
7.4.5 Help Manage Your Store . . . . . . . . . . . .
7.4.6 Protect Your Information and Your Shoppers
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7.4.7 The IBM Net.Commerce Administrator
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7.4.8 Site Manager and Store Manager
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7.4.9 Template Designer
7.5 Java for the AS/400 - A White Paper
7.5.1 Java Overview . . . . . . . . . . .
7.5.2 Why Java for the AS/400 System?
7.5.3 Java on the AS/400 System Today
7.5.4 Summary . . . . . . . . . . . . . .
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Chapter 8. Internet Application Performance . . . . . . . . . . .
8.1 Internet Application Performance Overview . . . . . . . . .
. . . . . . . . . . . . . .
8.1.1 How Fast Can a Web Site Go?
8.1.2 How Many Connections per Second is Enough? . . . .
. . .
8.2 Internet Connection Performance for AS/400 System
8.3 AS/400 Commercial Processing Workload (CPW) . . . . . .
8.3.1 AS/400 Advanced Server Models V3R7 . . . . . . . . .
. . . . . . . . . . . . . .
8.4 Web Serving with the HTTP Server
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8.4.1 Web Serving Performance Measurements
8.4.2 AS/400 HTTP Server Performance . . . . . . . . . . . .
. . . . . . .
8.5 Web Serving Performance Recommendations
8.5.1 CISC versus RISC . . . . . . . . . . . . . . . . . . . . . .
8.5.2 Response Time (General) . . . . . . . . . . . . . . . . .
8.5.3 HTTP and TCP/IP Configuration Tips . . . . . . . . . . .
8.5.4 HTTP Server Memory Requirements . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
8.5.5 AS/400 Model Selection
8.5.6 File System Considerations . . . . . . . . . . . . . . . .
8.5.7 File Size Considerations . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
8.5.8 Communications/LAN IOPs
8.6 Net.Data and DB2WWW . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . .
8.7 5250/HTML Workstation Gateway
8.7.1 Workstation Gateway Performance Recommendations
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8.8 Net.Data Performance, Hints, and Tips?
. . . . . . . . . . . .
8.9 CGI-Bin Performance, Hints, and Tips
8.10 Workstation Gateway, Hints, and Tips . . . . . . . . . . . .
Appendix A. ILE RPG and ILE COBOL Sample CGI Programs
A.1 ILE RPG Sample CGI Program CUSTINFO . . . . . . . . .
A.2 ILE Cobol Sample CGI Program CUSTINFO . . . . . . . .
A.3 HTML Input Form for CUSTINFO . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . .
A.4 DDS for the CUSTPF file
Appendix B. HTML Gateway Code Examples . . . . . . .
B.1 HTML Field Overlap Examples . . . . . . . . . . . . .
B.2 Logon Exit Code Examples for Workstation Gateway
Appendix C. Special Notices
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Appendix D. Related Publications
. . . . . . . . . . . . . . . .
D.1 International Technical Support Organization Publications
D.2 Redbooks on CD-ROMs . . . . . . . . . . . . . . . . . . . .
D.3 Other Publications . . . . . . . . . . . . . . . . . . . . . . .
How to Get ITSO Redbooks
. . . . . . . . . .
How IBM Employees Can Get ITSO Redbooks
How Customers Can Get ITSO Redbooks . .
. . . . . . . . . . .
IBM Redbook Order Form
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Contents
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Index
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ITSO Redbook Evaluation
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Figures
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 Copyright IBM Corp. 1997
Internet World Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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The Simple Web Model
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The Interactive Web Model
The Distributed Web Model . . . . . . . . . . . . . . . . . . . . . . . . . .
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The Enterprise Distributed Web Model
Internet Application Design Overview . . . . . . . . . . . . . . . . . . . .
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HTML Document
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HTML Document Displayed Through an OS/2 Web Browser
Clickable World Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Defining Hotspots and Associated URLs
Image Map Coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Mapping of Image Map URL to HTTP Configuration
AS/400 File Systems, File Server, and Integrated File System Interface
JavaScript Library Test Page (Part 1) . . . . . . . . . . . . . . . . . . . .
JavaScript Library Test Page (Part 2) . . . . . . . . . . . . . . . . . . . .
Roadmap for Internet Application Design . . . . . . . . . . . . . . . . . .
The Basic Idea of How the CGI is Working . . . . . . . . . . . . . . . . .
Ways of Communication for CGI Programs . . . . . . . . . . . . . . . . .
The HTML Source using the FORM Tag . . . . . . . . . . . . . . . . . . .
The HTML Document Using the FORM Tag Displayed by the Browser
The HTML Output Information Back on the Browser . . . . . . . . . . .
Mapping of CGI URL to HTTP Configuration . . . . . . . . . . . . . . . .
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AS/400 CGI Using the GET Method
AS/400 CGI using the POST Method . . . . . . . . . . . . . . . . . . . . .
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Two Named Input Fields Defined in the HTML Form
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CGI Programming with C Language using POST Method
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CGI Programming with RPG Language using POST Method
QUSEC Data Structure for Error Reporting . . . . . . . . . . . . . . . . .
RPG Source Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Getinput Subprocedure Sample
CGI Programming with REXX Language using POST Method . . . . . .
REXX Source Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The HTML Document using the FORM Tag with Method=GET . . . . .
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Document Returned from the Program CGIENVGET
The HTML Document using the FORM Tag with Method=POST . . . .
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Document Returned from the Program CGIENVPOST
Welcome to the ITSO Company Example . . . . . . . . . . . . . . . . . .
ILE RPG Program ORDAS400G Method=GET . . . . . . . . . . . . . . .
ILE RPG Program ORDAS400P Method=POST . . . . . . . . . . . . . .
ILE C Program PARSECGIP Method=POST . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net.Data Overview
Net.Data General Overview . . . . . . . . . . . . . . . . . . . . . . . . . .
Net.Data Macro Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Define Section of Web Macro . . . . . . . . . . . . . . . . . . . . . . . . .
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Function Definition Section
HTML Section: Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Browser View of Input HTML . . . . . . . . . . . . . . . . . . . . . . . . .
HTML Section: Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Browser View of HTML Output . . . . . . . . . . . . . . . . . . . . . . . .
RPG Program Called from Net.Data . . . . . . . . . . . . . . . . . . . . .
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RPG Program Input Window
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RPG Program Report Window
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REXX Calls RPG Program COUNT . . . . . . . . . . . . . . . . . . . . . .
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Net.Data Table View
Message Block Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Macro REXXM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REXX Source of TREXX.MBR . . . . . . . . . . . . . . . . . . . . . . . . .
Contents of QGPL/QSQCLIPKG . . . . . . . . . . . . . . . . . . . . . . . .
Simple SQL Command Function . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Function Macro
Using Include Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Include File TIMERFTN . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INCLUDE File TIMERSTR . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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INCLUDE File TIMEREND
Net.Data Environment Variables Macro . . . . . . . . . . . . . . . . . . .
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Sample of Net.Data Environment Variables
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Macro to Get Environment Variables
Sample Output of Environment Variables . . . . . . . . . . . . . . . . . .
Net.Data Select Box Macro . . . . . . . . . . . . . . . . . . . . . . . . . .
Sample Select Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
Copy to Stream File with ASCII Conversion
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Get and Post Statements
Map and Exec Statements . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Contents of Net.Data Initialization (INI) File
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Sample Net.Data URL
A Typical Company Showing the HTML Gateway Link to the Internet .
Workstation Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
5250-HTML Gateway Implementation Route
CFGTCPWSG Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . .
Change Workstation Gateway Attributes Display
. . . .
The AS/400 Sign-on Display Seen by the Workstation Gateway
The Command Entry Display Seen by the Workstation Gateway . . . .
The Work with Active Jobs Display Seen by the Workstation Gateway
DDS Source for Customer Comment Inquiry Display . . . . . . . . . . .
Customer Comment Inquiry DDS on the Traditional Text 5250 Display
A Portion of the HTML Automatically Generated by the HTML Gateway
Display of Customer Master Record through Workstation Gateway . .
Display of Subfile Record through 5250-HTML Gateway . . . . . . . . .
. . . . . . . . . . . . .
Sample 5250 DDS Enhanced with the HTML Tag
Link, Table, and Images Imbedded in DDS . . . . . . . . . . . . . . . . .
CL Program Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
RPG Program Example
COBOL Program Example . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .
AS/400 Firewall Technology Preview
Internet Connection Secure Server Preview . . . . . . . . . . . . . . . .
Distribution of Connections . . . . . . . . . . . . . . . . . . . . . . . . . .
AS/400 Relative Performance - CPW for Advanced Server Models V3R7
AS/400 HTTP versus CGI-Bin versus Net.Data . . . . . . . . . . . . . . .
. . . . . . . .
AS/400 HTTP Server Performance, Simple Page Serving
AS/400 File Size Variation . . . . . . . . . . . . . . . . . . . . . . . . . . .
5250/HTML Workstation Gateway Comparison . . . . . . . . . . . . . . .
Sample Exit Program for HTML Gateway . . . . . . . . . . . . . . . . . .
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 Copyright IBM Corp. 1997
HTML Main Elements . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
HTML Form Tags
CGI Environment Variables in the QTMHENVI Index File . . .
The APIs Provided for ILE RPG, ILE COBOL, and C Programs
. . . . . . . . .
Get Environment Variable (QtmhGetEnv) API
. . . . . . . . . . . . . . .
Read from Stdin (QtmhRdStin) API
Write from Stdout (QtmhWrStout) API . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . .
Convert to DB (QtmhCvtDb) API
Overview - Programs HTMLFILE=INPUT . . . . . . . . . . . .
Net.Data Function Definitions . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .
Net.Data Calling Functions
Net.Data %REPORT Block . . . . . . . . . . . . . . . . . . . . .
Net.Data REXX Language Environment Variables . . . . . . .
Net.Data SYSTEM Language Environment Variables . . . . .
. . . . . . . . . . . . . . . . . . . .
Message Block Definitions
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User Exit Program Extensions
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xii
Unleashing AS/400 Applications on the Internet
Preface
This redbook is intended to give directions to enable an AS/400 application to
the Internet. It gives you the necessary information to implement and run the
Internet-related AS/400 applications using one or a combination of the following
available techniques:
•
•
•
•
Common Gateway Interface (CGI-Bin)
Net.Data
Workstation Gateway
Java Applets and Java Scripts
It is also the intent of this redbook to provide you with a road map of the AS/400
application development scenario for the Internet and performance
considerations.
This redbook was written for technical services and consultants who are charged
with the task of recommending and implementing an AS/400 network computing
environment, and for the IBM, Business Partner and customer technical
professional community.
Some knowledge of the AS/400 system, application development, and Internet
programming is assumed.
The Team That Wrote This Redbook
This redbook was produced by a team of specialists from around the world
working at the International Technical Support Organization Rochester Center.
Ana Vallano Romero is a Systems Programmer working
for Ecinsa, an IBM Business Partner in Madrid, Spain.
She holds a degree and diploma in Computer Science.
Her areas of expertise include Internet, CGI-Bin, and C
language programming. She has more than 3 years of C
programming and technical support experience with the
IBM RS/6000 systems.
Jan P. Collins is a Systems Consultant working for
Datalink International, an IBM Business Partner in
Guernsey, England. During the past year, he has been
actively involved in integrating his company′s existing
AS/400 applications with the Internet. He holds a degree
and diploma of engineering in Naval Architecture from
England, but his most recent areas of expertise include
Internet, TCP/IP, Windows 95, HTML, and Java. He has
more than 15 years of scientific programming and
technical report writing.
 Copyright IBM Corp. 1997
xiii
Paul E. Hampton is an AS/400 Evangelist in the USA. He
has 20 years of experience working with IBM customers
and clients with S/36, S/38, and AS/400 Communications
and Performance. During the last two years, he has
helped several clients plan and execute successful
AS/400 intranets and Internets.
Gottfried Schimunek is an IBM Chief Systems Engineer
for the AS/400 system in Germany. He has more than 25
years of experience in the area of DP and IT systems,
especially on IBM System/3x, System/38, and the AS/400
system. His areas of interest and expertise include
AS/400 Architecture, System and Application
Performance, and Internet Connection. He coauthored
books about AS/400 Performance Management, Capacity
Planning, Client/Server Performance, and SAP R/3.
Fernando R. Zuliani is an AS/400 Certified I/T Specialist
in the ITSO Rochester. He has 10 years of experience in
the I/T field. He has worked at IBM for 9 years. His
areas of expertise include OS/400, Client/Server,
VisualAge Generator, Application Development, and
Performance. He holds a master′s degree in
Mathematics from the University of Sao Paulo, Brazil.
Thanks to the following people for their invaluable contributions to this project:
Allan E. Johnson
Systems Performance - AS/400 Development, IBM Rochester
Bill C. Rapp
Internet Technologies - AS/400 Development, IBM Rochester
Brian R. Smith
AS/400 Communications, ITSO Rochester Center
Daryl E. Woker
Internet Security and Firewalls - AS/400 Development, IBM Rochester
David D. Money
Network Computing - AS/400 Partners in Development, IBM Rochester
Jason Hunt
Network Computing - AS/400 Partners in Development, IBM Rochester
Jim J. Herring
Internet Technologies - AS/400 Development, IBM Rochester
Jose Carlos Duarte Goncalves
Network Computing, IBM Sao Paulo, Brazil
xiv
Unleashing AS/400 Applications on the Internet
Marcela Adan
Internet Security and Firewalls, ITSO Rochester Center
Mark A. McKelvey
Internet Security and Firewalls - AS/400 Development, IBM Rochester
Mel L. Rothman
CGI-Bin Programming - AS/400 Customer Technology Center, IBM Rochester
Mike W. Schroeder
Net.Data/Internet - AS/400 Development, IBM Rochester
Nadir K. Amra
Net.Data/Internet - AS/400 Development, IBM Rochester
Paul D. Brown
Network Computing - AS/400 Partners in Development, IBM Rochester
Comments Welcome
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Preface
xv
xvi
Unleashing AS/400 Applications on the Internet
Chapter 1. AS/400 System in Network Computing Environment
This redbook is intended to give directions to enable an AS/400 application to
the Internet. It gives you the necessary information to implement and run the
Internet-related AS/400 applications using one or a combination of the following
available techniques:
•
•
•
•
Common Gateway Interface (CGI-BIN)
Net.Data
Workstation Gateway
JAVA Applets and JAVA Scripts
It is also the intent of this redbook to provide you with a road map of the AS/400
application developing scenario for the Internet and performance considerations.
This book, the same as other IBM redbooks, mentions related areas such as IBM
offerings and AS/400 solutions.
As you may have seen, most product or solutions providers are offering many
kinds of Internet services. As well as an Internet connection for the AS/400
system, IBM offers:
•
•
•
•
•
Client and server software
Firewalls
IBM networking services
IBM information super highway solutions
IBM global network
In this chapter, we talk about:
Topic
Please see
What is the Internet
See Section 1.1, “What is the Internet” for more
information.
History of the Internet
See Section 1.2, “History of Internet” on page 2 for
more information.
Network Computing
See Section 1.3, “Network Computing” on page 3
for more information.
Why AS/400?
See Section 1.4, “Why Attach an AS/400 System to
the Internet?” on page 4 for more information.
1.1 What is the Internet
The Internet is the network of networks. It is an interconnection of many smaller
networks forming a larger network we call the Internet. As the number of hosts
and other networks connecting to the Internet grow, so does the Internet.
Since the Internet′s conception, applications and protocols have been developed
to utilize it. The popularity of applications such as FTP and e-mail caused a
meteoric rise in the number of users connecting to the Internet. More recently,
however, the World Wide Web is the area of usage showing the most rapid
growth.
 Copyright IBM Corp. 1997
1
The original backbone of the Internet was provided by the U.S. Government,
science institutes, and universities as a means of sharing research data. As
usage has outgrown the original infrastructure, it has been continually upgraded
by communications companies funded by the subscriptions of the end users.
Figure 1. Internet World Map
This picture shows all of the current countries in the world and indicates by
different shades of black through white the level of Internet access. White
indicates full Internet access, which makes up most of this world map.
1.2 History of Internet
The Internet was born in the late 1960s as an effort to create a United States
Department of Defense network called ARPANET. The main purpose for it was
to connect defense contractors and universities that were working on projects for
the Department of Defense.
In 1973, the ARPANET established connections to England and Norway, and in
1982, the TCP/IP became the protocol suite for ARPANET. This leads to one of
the first references to an ″Internet″ of connected networks.
In 1983, the University of Wisconsin developed the name server that was
introduced in 1984.
In 1986, NFSNET was created with a backbone speed of 56 Kbps and upgraded to
T1 (1.544 Mbps) in 1989.
In 1989, the AS/400 system started supporting TCP/IP on Release 2.0 of OS/400  .
This was even before we knew that this was version 1!
2
Unleashing AS/400 Applications on the Internet
Gopher was introduced by the University of Minnesota in 1991. WWW (World
Wide Web) was released by CERN in 1992 adding to established and popular
applications such as Telnet, e-mail, and FTP.
Today, we have an estimated 4 000 000 hosts connected to the Internet and many
more connected to internal ″intranets″. Network providers have upgraded the
speeds of their backbones to T1, T2, T3, and so on to cope with the rising
demand for bandwidth.
Now, with the Internet on the verge of becoming a huge commercial
marketplace, the challenge is to create a suitable environment for secure
electronic commerce.
Here are some interesting Internet facts:
•
U.S.A. corporations establish a new site on the Internet every 12 minutes Internet Society.
•
By early 1996, there were 170 000 commercial sites on the Internet worldwide
- InterNIC.
•
U.S.A. shoppers purchased 436 million U.S. dollars worth of goods and
services over the World Wide Web in 1995 - ActivMedia.
•
In 1996, 81% of the top 200 U.K. companies viewed the Internet as a
business opportunity with more than one-third already having an Internet site
- Barclays Bank.
•
In Asia, Europe, and the U.S., about 17.6 million people are expected to be
connected to the Internet by the end of 1996, up from 10.6 million in 1995 Forrester Research.
•
Fifty years after the invention of the telephone, world residents had made a
total of 38 million phone calls. Today on the Internet, around 38 million page
visits occur every 24 hours - SRI International.
1.3 Network Computing
The latest stage in the computing industry′s evolution is the client/server model
in which end users (clients) are able to use the services of multiple host systems
(servers). These customers require highly effective products, services, and
solutions to help integrate all of the legacy data from distributed systems. This
takes us to the Network Computing (NC) model.
An example of the Network Computing model can be:
A single AS/400 system accessing vast amounts of data, stored on many
different systems across a large network as if it were stored on a single entity.
End users perceive information, applications, and services as being provided by
the network rather than by a computer system. IBM is committed to Network
Computing on the AS/400 system, a system that has the advantages of an
integrated database, integrated security, and an object-based structure.
The AS/400 users can utilize the latest technology, reduce or eliminate many
geographic barriers, exploit the Internet to their companies, and enable new
ways of doing business.
Internet Connection for AS/400, which is an integrated package included with
OS/400, helps customers conduct business on the Internet. It includes:
Chapter 1. AS/400  System in Network Computing Environment
3
•
World Wide Web Hypertext Transfer Protocol (HTTP) server
•
Workstation Gateway (WSG) server
•
Net.Data
•
Logging of World Wide Web server access
TCP/IP has also been enhanced to provide:
•
FTP support across all of the Integrated File System (IFS).
•
FTP authentication exits points (Anonymous FTP).
•
Asynchronous communications support in the form of SLIP.
Reference: URL http://www.as400.ibm.com
1.4 Why Attach an AS/400 System to the Internet?
Why not? If you are seriously considering putting a server onto the Internet,
there are many distinct advantages in choosing an AS/400 system. If you have
concerns about using an AS/400 system in this role, ask yourself whether the
reason for your concern (such as security) is associated with the Internet itself
rather than a specific system.
Consider the advantages of using an AS/400 system:
4
Communications
An AS/400 system has exceptional communication
capabilities. LAN, WAN, and dial-up capability are all part and
parcel of OS/400 providing a choice of connection methods
using TCP/IP.
Scaleability
The common features present in OS/400 across the entire
model range make it easy to accommodate future growth.
Functionality
The AS/400 system provides the popular TCP/IP applications
such as Telnet, FTP, e-mail, WWW server, and so on.
Software cost
Almost all the AS/400 TCP/IP suite of applications comes free
of charge when you order OS/400.
Training
If you are already running an AS/400 operation, the training
required to attach your AS/400 system successfully to the
Internet is minimal.
Security
The AS/400 system has extremely good, native, security
features. These features alone can prevent many
Internet-related security problems that afflict other systems.
With user-exit programs, you can further enhance the security
for FTP and Workstation Gateway servers.
Legacy Data
Perhaps the main reason to consider an AS/400 system as an
Internet server is when the information you want to serve is
already resident on an AS/400 system. The new Internet
Connection for AS/400 applications provide several methods
of accessing your legacy data through the Internet. By using
the Workstation Gateway server, most of your existing
″green-screen″ applications are Internet enabled now. With
Net.Data, you can access your legacy data from WWW pages.
With CGI-BIN programs, you can build new applications to be
used from WWW pages.
Unleashing AS/400 Applications on the Internet
Chapter 2. Internet Application Design Considerations
Millions of people are now connected to each other through the Internet, creating
a magnificent spectrum of new application possibilities. This topic discusses the
AS/400 specific Internet application capabilities.
2.1.1 Network-Centric Computing
The Internet is becoming more and more popular. Every day thousands of new
users are entering cyberspace. They all are looking for, using, and exchanging
information on the many servers that form the backbone of the Internet. The
World-Wide Web (WWW) gives these users a single interface to these servers
and so offers easy access to an overwhelming amount of information about
almost everything on this planet.
However, the information presented on the pages of the WWW used to be
essentially static. Using a Web browser, a user could access the information on
the Web but could not change or manipulate it in real time. This changes with
the availability of AS/400 Internet Connection (CGI-Programming, Net.Data, and
Workstation Gateway). (We cover these functions in great detail in the following
chapters.)
This will again change in the future when small programs, called applets, are
linked from Web pages, downloaded to the Web browser and executed on the
client machine. The technology that makes this possible and secure is the
Java  run-time environment designed for this purpose by Sun Microsystems.
IBM has licensed the technology from Sun Microsystems and will use it on its
platforms; beta versions of the Java toolkit for OS/2  , AIX  , and others are
already available on the Internet (see:
http://ncc.hursley.ibm.com/javainfo
Java applets can be written in any language that can be compiled to the Java
instruction codes. One such language is called Java, a simplified derivative of
C + + . IBM is actively investigating alternatives to the Java language for
programming the Java environment. For more detailed information, see
Chapter 6, “Further Enhancing Your AS/400 HTML Pages” on page 221.
2.2 AS/400 Internet Application Scenarios
When discussing AS/400 systems and the Internet, one needs to consider the
various roles the system may play since they affect the design and technology
requirements for an application.
•
Public Internet Presence
The AS/400 system can be a public server (for example, Web server) that is
accessed directly by users from the Internet. The users that access the
system are often not known in advance. Some services are generally open
to the general public while others are reserved for authorized users.
•
Internet Accessible
The AS/400 system is a private system that is accessible by authorized users
from the Internet; the Internet merely provides a convenient means for
access.
 Copyright IBM Corp. 1997
5
•
Internet Access
A private AS/400 system accesses servers attached to the Internet (for
example, AS/400 users FTP to Internet servers to obtain software fixes).
•
Intranet
A private AS/400 system is part of an internal corporate network that uses
Internet-based protocols.
•
Extranet
Networks that extend beyond a single company to multiple organizations that
must collaborate, communicate, and exchange documents to achieve joint
goals. These networks take a company′s existing intranet and extend it
beyond the enterprise to enable collaborative business applications such as
electronic commerce and supply-chain management or between one
company and its customers and suppliers.
A given AS/400 system may take on multiple roles at the same time.
2.3 Different Web Models
Within each Net previously described, there are four distinct and different ways
to present or to interact with the Web user:
2.3.1 Simple Web Model
The simple Web model consists of publishing static Web pages using the
Hypertext Markup Language (HTML). The Web browser opens up a connection
to the Web server and the server returns a page and closes the connection.
This model is suitable for providing access to business information that is
relatively stable. It originally provided the foundation for the Web. Although
later enriched by extensions to HTML (such as tables and frames), the simple
Web model remains a static model. The user′s only interactive options are
limited to clicking on a link to visit another page or requesting a page reload.
6
Unleashing AS/400 Applications on the Internet
Figure 2. The Simple Web Model
2.3.2 Interactive Web Model
In the interactive Web model, pages can contain forms, fields, and buttons that
allow users to enter data and choices. When they complete the forms and make
their choices, the browser opens a connection with the server to allow the data
and choices to be transmitted. The Web server passes the information to a
custom server program or script that makes an inquiry or does calculations and
passes back a new page for the browser to display. The connection is closed.
The interactive Web model supports a simple form of client/server computing
using Hypertext Transfer Protocol (HTTP) as the middleware and the Web
server′s Common Gateway Interface (CGI) that calls a custom server program or
script. This model works well for simple interactions that do not require high
inter-activity between the client and server. However, it is quite expensive in
terms of server resources and time when establishing a connection between the
browser and the server for each interaction.
Chapter 2. Internet Application Design Considerations
7
Figure 3. The Interactive Web Model
2.3.3 Distributed Web Model
The distributed Web, also known as Internet PC, introduces Java. With Java, a
small application called an applet can be transmitted to the browser along with
the Web page. The Java applet runs within the browser as users view the page.
It can provide lively animation or sound as well as rich graphical user interface
components such as the ones usually found on windowed PC applications. The
applet can display a window or be displayed in a Web browser; it can also
process user input. If server interaction is needed, the applet can open a
connection to the Web server to access a server or script through the Web
server′s CGI. The distributed Web model enriches the user interface and
off-loads tasks from the Web server (such as parameter checking in the
browser), but it is still tied to HTTP for communications. The next section
describes another model that supports additional communication protocols.
8
Unleashing AS/400 Applications on the Internet
Figure 4. The Distributed Web Model
2.3.4 Enterprise Distributed Web Model
An additional application model that IBM intends to support is called the
Enterprise Distributed Web model. Enterprise Distributed Web applications are
true open client/server applications. The client is coded in downloadable Java,
which runs in any Java-capable browser. A page containing the Java applet is
downloaded by a Web server to a browser. While the applet runs in the
browser, it opens its own communications session to the server. The applet also
communicates with a server to provide access to the database, C++, Java
application servers, or SOM  objects, in addition to supporting a variety of
middleware, include HTTP, TCP/IP, Secure Sockets Layer (SSL), DSOM, and MQ.
Chapter 2. Internet Application Design Considerations
9
Figure 5. The Enterprise Distributed Web Model
2.4 AS/400 System Facilities for the Internet
This section gives an overview of the Internet-related services on the AS/400
system.
2.4.1 Database Services
The AS/400 database is accessible to Internet users through CGI programs and
the Net.Data product. Net.Data uses a modified type of HTML file called a macro
that includes HTML script as well as directives that allow dynamic documents to
be built. These directives can be SQL statements, program invocations, include
statements, and variable substitutions. Local and remote AS/400 databases can
be accessed from a Net.Data macro. For more information, refer to the Net.Data
description in Chapter 4, “Net.Data Implementation” on page 111.
2.4.2 Application Access
Existing (legacy) applications can be accessed using the 5250 Workstation
Gateway function.
New internet applications can be written using HTTP server APIs, the CGI
interface, or using the Net.Data product. HTTP server API programs can be
written in the C programming language. CGI programs can be written in C, RPG,
10
Unleashing AS/400 Applications on the Internet
and COBOL programming languages. Net.Data applications are written in a
macro language that can reference AS/400 resources including the database and
programs written in a variety of AS/400 languages (C, C++, COBOL, RPG,
COBOL, REXX, and PERL).
All of these functions are available as part of OS/400.
Lotus Domino is another way of serving up Internet applications. Domino allows
applications to be built using the rich application development capabilities of
Lotus Notes. Domino allows existing Notes applications to be served up over the
Web.
PERL has been ported to the AS/400 system by Mortice Kern Systems Inc.
(MKS). More information about MKS can be found on the Web under the URL:
http://www.mks.com
This product was put out as a product preview option in December 1996.
2.4.3 Content Authoring
Internet content authoring for the AS/400 system is typically done using a PC
editor or graphical tool. The content (HTML text, Net.Data macros, Java applets,
images, audio, video, and so on) is created and tested on the PC and uploaded
to the AS/400 IFS where it can be served to Internet clients.
2.4.4 Content Management
Internet content management deals with the difficult job that a Web administrator
has of managing Web objects including HTML scripts, macros, CGI programs,
Java applets, audio/video clips, bitmaps, and the links that tie them all together.
It also deals with being able to determine how a Web site is navigated through
navigation analysis tools.
A technology demo for a management tool (Visual Web Manager) is available at
IBM on the Internet. Visual Web Manager allows you to view the structure of
your Web site and HTML presentations and make modifications on the fly.
Visual Web Manager gives you a simple visual environment in which you can
develop and maintain your Web site.
The demo version of the software is suitable for small-to-medium sized Web
sites that contain a maximum of 500 HTML pages. The software runs locally on
your machine (which can be your server or any other machine where you
develop a Web site or presentation) and operates on Web sites where the HTML
pages are contained within the directory containing the home page or
subdirectories under this directory.
The best way to become familiar with the software is to run it on the demo
presentation that is supplied with the software. See the instructions in the
README for running the demo presentation. For more information and to
download a Beta version of an Internet Visual Web Management Tool, see:
http://www.ics.raleigh.ibm.com/ics/icfbetas.htm
Chapter 2. Internet Application Design Considerations
11
2.4.5 Java Development Environment
VisualAge  Java for the AS/400 system includes a suite of visual builders for
interactively building Java applications on client machines including OS/2 and
Win95/NT clients. It includes an integrated development environment with a
project manager, class browser, editor, and debugger. It also includes a set of
remote debug classes that allow a Java application written on the AS/400 system
to be debugged from a client machine. Other OEM tools can also be used to
build AS/400 Java applications.
2.5 General Design Considerations
There are some general design considerations to be taken into account when
writing or modifying applications for the Internet. The following sections cover
some of the major design considerations and differences to native AS/400
application design.
2.5.1 Transactions over the World Wide Web using the Internet
Running an AS/400 application over the Internet can be quite different to what
applications do in a ″normal″ environment. Since there is no constant
connection between the server and the client, there is no transaction flow that is
controlled from the server. The user typically gets a window (HTML), looks at it,
changes some fields, and sends it back.
The user might also decide after receiving the data to do something else and not
do anything with the data. So the server program cannot rely on the fact that
since it sent some data, it is suppose to get some data back.
There is also no control over the arrival of the data; the data might get stuck on
the wire and never see the end user. The server does not recognize it.
2.5.2 Synchronization between Web Browser and Server
This section discus how the requests are synchronized between the Web
browsers and the Web server.
2.5.2.1 Sending Multiple Requests
Most of the applications on the AS/400 system do not allow you to submit a
further request while another request is currently processing. This is due to the
fact that during this time, the application is not sensitive for user input. With a
Web browser, this is not the case. A user is allowed to request a new document
or post data while another request is currently processed by a server. For
example, this may happen when a user unintentionally double-clicks a button.
Usually the second request causes the browser to discard the answer to the first
one.
2.5.2.2 History Mechanism and Caching
Also with a native application, it is not possible to switch to another window
without server communication. Browsers often have history mechanisms such
as ″Back″ buttons and a history list that can be used to re-display a page from
the cache retrieval earlier in the session. A history mechanism is meant to
show exactly what the user saw at the time when the resource was retrieved on
condition that the resource is still in the cache.
12
Unleashing AS/400 Applications on the Internet
2.5.2.3 Transaction Context
In the beginning, browsers were used to retrieve inter-related documents. No
context was kept by the HTTP server related to a user session. Here it made
sense to switch back to another page without communication to a server even if
the page was outdated. But to re-display a page from a cache does not make
sense for transactions. Here a page should reflect the current transaction state.
With transactions, a page also contains forms for posting data to a server in
contrast to links that are (usually) used to request other documents. These
forms make sense only in a certain context.
2.5.2.4 GET and POST
The GET method is always used in the HTTP request for links. For forms, the
method is determined by the form attribute ″method″, which should be set to the
POST method.
2.5.2.5 Caching Strategies for GET and POST
When using history mechanisms, the Web browser always tries to retrieve the
page from cache. But when submitting a form or selecting a link, we must
differentiate between the POST and GET method. When resubmitting a form with
a POST method, the Web browser never tries to retrieve the page from cache
even if the posted data is the same. Here the request is always submitted to the
server in contrast to pages retrieved with a GET method.
2.5.2.6 Caching Control
It is possible for the server to request no caching for a page. Here the field
″expires″ (which is set to 0 in the HTTP header) and prevents caching. It is also
possible to request no caching for an HTML document by using:
<meta http-equiv=″expires″ content=″0″>
in the header part of the HTML document.
2.5.3 End User Driven
Also different is the way the application is being driven. On the Internet, the end
user determines the flow of the application. This is similar to a client/server
application with a GUI front end where the user picks and chooses icons and
menu items not controlled by the application. The user might decide to request
some data from one server, request different data from the same server, data
from different servers, and finally after hours, fills the first window and returns it
to the first server.
To always have complete transactions, the server application has to send a
simple, complete transaction on one request, or has to keep track of each user′ s
status. Most AS/400 applications today presume that the calling user stays with
the application until it finishes it. Most of the transactions span several windows
before a customer transaction is complete.
2.5.4 End User Anonymous
On the Internet (or intranet, for that matter) end users are anonymous, or
unknown to the application when they request information from the server for the
first time unless one of the first requests contain sign-on information such as
USERID and password. The nature of how a user communicates to the server is
again different than what we currently have in a typical AS/400 environment.
Chapter 2. Internet Application Design Considerations
13
2.5.5 Status of User Requests
In a native AS/400 environment, there is a one-to-one relationship between one
user and an invocation of the application program (one job per user). Also, it is
quite common for an application that needs more than one transaction to the
user to complete one business transaction. Because it is always the same user
talking to the same program invocation, it is relatively easy to keep track of what
the user did and what the next steps should be.
In the Internet server environment, however, each dialog is separate from each
other and it is probably going to use another server job. So, there is no
information being kept on the server regarding the client.
To keep track of a particular user and what it has processed so far, you can use
what is called a cookie or hidden fields, a feature inside the browser. The
following sections describe how cookies and hidden fields can be used.
2.5.5.1 How Cookies Work (Client Side Persistent Information)
A ″cookie″ is a small piece of information that a Web server can ask the browser
to store temporarily.
Note
Not all browsers support ″cookies″ so it violates the rule of being a browser
independent application.
A program can test for HTTP_USER_AGENT and use ″cookies″ if supported,
or else use hidden fields or other available mechanisms.
This is useful by having the browser remember some specific information that
the Web server can later retrieve. For example, when you browse through a
″virtual shopping mall″ and add items to your ″shopping cart″ as you browse, a
list of the items you pick up is stored by your browser so that you can pay for all
of the items at once when you are finished shopping. It is much more efficient
for each browser to keep track of information instead of expecting the Web
server to remember which browser (of the thousands of browsers that might be
using it at a time) bought what.
As you browse the Web, cookies sent to your browser are stored in memory.
When you quit the browser, any cookies that have not expired are written to a
cookie file so they can be reloaded the next time you run the browser. (On a
Mac, this file is named ″MagicCookie″; on UNIX  , it is ″cookies″, and on
Windows , it is ″cookies.txt″. Contrary to popular belief, a cookie file is not a
secret way for a Web server to find out everything about you and what you have
on your hard drive. The only way that any private information is in your cookie
file is if you personally gave that information to a Web server in the first place
and it decides to put that information into your cookie file for some reason.
There is absolutely no way for a Web server to get access to any private
information about your system through cookies.
To create a cookie, a Web server sends a ″Set-Cookie″ HTTP header line such
as this one in response to a URL access from a browser:
Set-Cookie: NAME=VALUE; expires=DATE; path=PATH; domain=DOMAIN_NAME;
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Unleashing AS/400 Applications on the Internet
NAME is the name of the value you are storing on the browser, and VALUE is the
actual data being stored in the cookie. DATE is the date and time at which the
cookie information expires and is ″forgotten″ by the browser (and removed from
the cookies file if it was written there). DOMAIN is a host or domain name for
which the cookie is valid (servers outside of that domain can never see this
particular cookie for security reasons). PATH specifies a subset of the URLs at
that server for which the cookie is valid (other URLs do not see the cookie).
The only required field is NAME=VALUE.
Whenever the browser sends an HTTP request for a URL on a server where it
has stored cookies (as long as DOMAIN and PATH match the URL), it includes a
line of the form:
Cookie: NAME=VALUE; NAME=VALUE; ...
A complete technical explanation of how cookies work is available on
http://home.netscape.com/newsref/std/cookie_spec.html
2.5.5.2 How Hidden Fields are Used
Hidden variables are used to conceal the actual name of a variable from people
who choose to view your HTML source with their Web browser.
T y p e = ″hidden″ defines an invisible input field whose value is sent along with
the other form values when the form is submitted. This is used to pass state
information from one script or form to another:
Hidden Field: INPUT TYPE=HIDDEN
An INPUT element with ″TYPE=HIDDEN″ represents a hidden field. The user
does not interact with this field; instead, the VALUE attribute specifies the value
of the field. The NAME and VALUE attributes are required.
Example:
<input type=hidden name=context value=″l2k3j4l2k3j4l2k3j4lk23″>
IMPORTANT!
Hidden fields are not totally safe; you can save and modify the HTML on the
browser and resend the modified HTML back to the server, which, in fact,
prevails the hidden fields.
Reference on the Internet
http://members.aol.com/htmlguru/tips/index.html
2.5.6 National Characters, Code Pages, Date Format
An Internet application that is supposed to give world wide support has to have
support for national characters as well as the corresponding date formats, date
separators, decimal position, and decimal characters. While in a native AS/400
application, this support is given by OS/400; in the Internet environment, it is up
to the application and the browser.
Chapter 2. Internet Application Design Considerations
15
It is a good practice to store language dependent code/HTML in separate
directories and allow the user to choose their language at the first window
(Welcome window).
2.5.6.1 CCSIDs and ISO Character Sets
While OS/400 uses CCSIDs to identify the way text data is encoded, the World
Wide Web uses ISO character sets to identify the way text data is encoded. The
following example shows some of the useful ISO character sets and associated
CCSIDs:
ISO character set
----------------US-ASCII
ISO-8859-1
ISO-8859-2
ISO-8859-5
ISO-8859-7
ISO-8859-8
ISO-8859-9
ISO-2022-JP
ASCII
CCSID
----367
819
912
915
813
916
920
5052
Note
Note that ISO-8859-1 (CCSID 819) is the default character set for HTTP.
Related Documentation
The following IBM manuals contain information that may be useful to you:
Character Data Representation Architecture Level 1
Character Data Representation Architecture Level 2
AS/400 International Application Development
AS/400 National Language Support Planning Guide Version 2
SC09-1390-00
SC09-1390-01
SC41-3603-00
GC41-9877-02
2.5.7 Internet - Intranet - Extranet Considerations
One of the major differences between running applications in the IntERnet versus
the intRAnet and the EXTRAnet is security (or the lack of it) and what kind of
information is presented to the user.
While using the intRAnet, all information is available to the users with the right
authority (for example; a sales person, to all sales and customer related data; a
book keeping person, to all personnel and human resource data, and so on).
On the IntERnet, however, everything should be disallowed except information to
be used by the public. Under more restricted access, users are allowed to see
and modify specific data, but always with the exposure of accidentally disclosing
this information also to the public (hackers).
The EXTRAnet can be viewed as a private net within the IntERnet or a private
network using either dialup or leased lines with it′s own security and encryption
algorithms. So data exchanged between businesses is pretty much safe.
However, here it is much more important to have a mechanism in place to make
sure that when you send something, the addressee knows exactly who sent it
and also keep a receipt for delivery to have proof of sending it.
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Unleashing AS/400 Applications on the Internet
2.5.8 Internet Application Error Recovery
Internet application error recovery is up to the application developer and the
program itself. Each programming model has different techniques to monitor
and handle error messages and is described in more detail either in Chapter 5,
“HTML Gateway Implementation” on page 169 for Workstation Gateway,
Chapter 4, “Net.Data Implementation” on page 111 for Net.Data, or Chapter 3,
“Common Gateway Interface (CGI-BIN) Implementation” on page 57 for CGI-Bin
programming.
2.6 Programming Alternatives
On the AS/400 system, there are several options available to support users on
the Internet.
The AS/400 system offers some alternatives to enable applications to the
Internet. One does not require any change to the application itself; it only has to
be enabled at the server side. Users can use AS/400 applications on the
Internet (intranet) as they are used to using natively on a terminal. The function
on the AS/400 system is called HTML Workstation Gateway and is part of
OS/400.
Another method is to provide an easy access to the data in the database and
allow queries to be executed, or call programs that access the database and
return the requested data.
The following diagram shows the different ways to support users on the Internet.
One might to decide to take one function only, some others might want to
combine two or even all available approaches.
Chapter 2. Internet Application Design Considerations
17
Figure 6. Internet Application Design Overview
Depending of what you want to get accomplished, you can choose either one or
a combination of the following options:
•
CGI - Common Gateway Interface
•
Net.Data - Interactive Data Publishing with Universal Access to Dynamic Data
•
HTML Gateway - Workstation Gateway
•
Java applets accessing the AS/400 system directly
The following sections explain each option (programming model) in more detail
to allow you to determine which one to use for your specific requirements.
2.7 Internet Programming Models
There are two dominant programming models currently in use today over the
Internet: the HTTP CGI programming model and the Internet client/server
programming model. The AS/400 system supports both of these models to
varying degrees.
18
Unleashing AS/400 Applications on the Internet
2.7.1 HTTP CGI Programming Model
The HTTP Common Gateway Interface (CGI) programming model provides a
simple interface for running programs external to the HTTP server in a
platform-independent manner. This interface has been in use by the World Wide
Web since 1993. A good document that describes this interface can be found at
URL:
http://hoohoo.ncsa.uiuc.edu/cgi/interface.html
The purpose of CGI is to extend the capability of an HTTP server by providing
framework in which the HTTP server can interface with a program that is
specified on a URL. The format of the URL allows parameters to be passed to
the CGI program. On the server side, the interface describes how the program
is started by the HTTP server and how parameters for the program are passed
using a combination of standard-input and environment variables. It also
describes how output information (usually HTML elements) are passed back to
the HTTP server using standard output. Thus, in its simplest form, a CGI
program can be defined as a program that:
1. Can be called as an executable and run as a child process of the HTTP
server (this does not preclude the use of interpretive languages such as
REXX and PERL. In this case, their respective interpreters run as child
processes of the HTTP server).
Note: The CGI program on the AS/400 runs within the same job as the HTTP
server.
2. Is able to read from the standard input.
3. Is able to access environment variables.
4. Is able to write to the standard output.
5. Is able to access ″command line″ arguments passed to main()
CGI programs can be as simple or as complex as the programmer wants to
make them, but clearly, the intent of the interface is to allow simple programs or
scripts to be developed quickly.
Given this definition of the CGI interface, the following characteristics are for CGI
programs:
•
They can be written in compiled programming languages or interpreted
scripts.
•
They can be simple five or six-line programs that serve a specialized
function or generalized business applications that do complex calculations
and database transactions (for example, order processing applications).
•
They are portable. As with any programming model, portability is a matter
of degree. To the extent that the program uses any operating system unique
interfaces or naming semantics, portability is reduced.
•
Since they run as a child process of the HTTP server, they can benefit from
the services provided by the server:
−
Communication over the HTTP protocol
−
Security
−
Firewall transparency. HTTP is usually allowed to pass through firewalls
(through socks or application gateways).
Chapter 2. Internet Application Design Considerations
19
−
Resource mapping and name indirection provided by HTTP server
directives (program can be moved without affecting client URLs.)
−
Error logging and audit logging provided by HTTP server
−
Course grained navigation provided by HTML documents
•
They provide process isolation. Since each CGI program runs in its own
child process, it has the security and integrity advantages that separate
processes offer.
•
They run in a connectionless environment. The HTTP server starts the CGI
program, it does its thing, and terminates. The output is sent to the browser
and the connection is broken. Subsequent requests for that same program
result in a new connection and a new instance. No state information is
maintained unless the CGI program had stored previous state information in
fields in the requesting HTML form or parameters in the requesting URL.
This characteristic comes about as a consequence of the Web′s hypertext
model that allows users to hop around from machine-to-machine across the
world at will. Forcing the browser to maintain persistent connections to all of
these machines is ridiculous.
•
Process start time often gates performance. The price to pay for process
isolation is to suffer the costs of process start time. In a connectionless
environment, this becomes an even bigger problem as the process must get
started for each request. The AS/400 HTTP model minimizes this penalty by
providing a pool of pre-started server jobs that minimize a majority of the
start-up costs. Add to that the ability to exploit named activation groups that
also eliminate program initialization costs, and the AS/400 CGI model starts
to look better than what is provided on other platforms.
•
They use short-running transactions. This is a consequence of the
connectionless model. The length of a transaction is limited to a single URL
request since that is the length of a process. This problem brings about the
requirement for the persistent CGI model described later.
•
The logic is almost entirely on the server. The CGI model is basically a
distributed presentation model where the logic is on the server and the client
is responsible for window presentation. The advantage of having the logic
on the server is apparent when the number of window interactions is far
smaller than the number of data accesses or the number of calculations
performed by the server.
Although the CGI model is simple and universal, it has some definite
shortcomings. This is primarily due to its connectionless nature.
20
•
CGI program parameter data (passed as part of the URL) has portions
encoded with escape sequences. It is cumbersome for CGI programs to
decode these sequences after they have been converted from ASCII to
EBCDIC.
•
It is difficult for the CGI programs to determine and control what CCSIDs to
use when handling ASCII and EBCDIC data.
•
Multiple conversions from ASCII to EBCDIC of input and output data presents
some performance problems.
Unleashing AS/400 Applications on the Internet
2.7.2 Java Applet Communicating to CGI
Another dimension that can be added to the HTTP CGI model is to make use of
Java applets running in the browser that communicate with CGI programs. It
turns out that the Java virtual machines built into browsers have mechanisms
that allow its applets to access HTML documents and CGI programs directly.
With this model, a CGI program may send to a browser HTML that includes a
Java applet. The Java applet may use HTTP to retrieve additional information
from the server such as data stored in a file or output from another CGI
program. This access is done independently of the browser session but using
the HTTP services built into the browser. Since the HTTP protocol is being used,
all of the advantages of HTTP are maintained including its authentication and
encryption features. No changes are required to standard CGI or persistent CGI
programs to support communications with a Java applet.
With this approach, logic can be split between the client and server with the
client Java applet doing more than just providing a pretty window presentation.
It can dynamically receive information from server files and programs at the
user′s request.
2.7.3 Net.Data Macros
Net.Data provides a convenient mechanism for creating dynamic Web pages
without complex programming. A user creates a dynamic HTML script called a
macro that is interpreted by the Net.Data macro processor. The macro
processor is implemented as a CGI program or a persistent CGI program (on
other platforms, it is also implemented as a server API program). The macro
contains HTML statements as well as macro directives that represent
substitution variables, SQL calls, or program calls. Macros can be used to build
complex forms and process information from those forms. They can also be
used to generate Java applet calls, Java script, and Visual basic script
statements.
2.7.4 The Internet Client/Server Programming Model
The second prominent Internet programming model is the Internet client/server
model. This model is not that different from the traditional client/server model
that allows program logic to be distributed between a client and a server
communicating over some agreed-to protocol. The Internet client server model
is different only in that Internet/intranet protocols are used (that is, something
that runs over TCP/IP) and the programming languages and associated tools are
platform independent (for example, Java).
What is attractive about the Internet client/server model (compared to the HTTP
CGI) model, is that the program logic can be distributed as appropriate between
the client and server, and a persistent connection is maintained allowing for long
running transactions. However, since the HTTP protocol and the HTTP server
are not being used for communications, it is the responsibility of client and
server pair to agree on what application protocols are used (for example,
roll-your-own over a sockets connection), and how things such as security,
encryption, integrity, translation, and such are handled. This becomes especially
difficult when dealing with transient Java applets.
For the purposes of this document, the Internet client/server programming model
is defined as Java applications or applets communicating to server applications
over Internet/intranet protocols. The server applications can be either new or
existing procedural servers or new Java servers.
Chapter 2. Internet Application Design Considerations
21
Why Java? Java is the common man′s OO language. It is much simpler than
C++ and it was designed for programming on the Internet. It comes with its
own distributable object model and it runs everywhere. Technically, Java is the
only language that deals with threads as part of its basic construction. This has
the potential of giving it scalability characteristics that are orders of magnitude
greater than the traditional process based model. And finally, Java is a good fit
for the AS/400 system. Its byte code architecture maps well to our MI
architecture and the fact that is uses no pointers makes it a natural for our
secure AS/400 execution environment.
2.7.5 Lotus Domino
Domino allows application developers to use the powerful application
development facilities of Notes to create Web applications. Notes includes its
own graphical forms designer, directory services, replication services,
messaging services, security, and workflow. Domino allows applications
developed with Notes to be accessible through the Web.
2.8 Supporting the AS/400 Legacy Programming Models
The previous discussion described the ″new″ internet programming models
available on the AS/400 system. It does not describe what we are doing to
support the thousands of programs and millions of lines of code implemented
with the AS/400 legacy programming models.
We use the legacy programming model here to describe those applications that
were probably written in COBOL or RPG and communicate to a 5250 workstation
using DDS. There is a well-defined set of tools and procedures available to
create, debug, and deploy these applications and our ISVs have invested a great
deal of time and money in training their developers to become proficient in this
area.
Eventually, we want those developers to become comfortable with the new
programming models and begin to re-tool their development processes. We
must realize, however, that this re-tooling is gradual at best. We, therefore,
have a responsibility to support and extend the existing legacy applications by
providing mechanisms to make them accessible over the Internet. Some of
these mechanisms allow this to happen transparently to the application. Others
require various degrees of modification to portions of the application.
We provide some of the following mechanisms to support our legacy
applications.
2.8.1 The 5250 Workstation Gateway
The 5250 workstation gateway is a specialized HTTP server that transforms the
5250 data stream into HTML on the fly. With the gateway, any browser can run
any AS/400 application with no modification to that application.
Functionally, this is the best Internet support we have for legacy applications. It
is completely transparent to the applications, works with system programs as
well as user programs, and can be accessed from any browser on the Internet.
There is a price to pay for this functionality and transparency (namely usability
and performance). Usability problems stem mainly from the fact that an Internet
browser does not have the same functional capabilities as a 5250 terminal and
22
Unleashing AS/400 Applications on the Internet
controller. It does not support function keys, it does not support special field
editing capabilities (such as mandatory fill, mandatory entry, numeric-only fields,
range checking, and check digit), and it does not maintain a persistent
connection with the host system. The 5250 gateway compensates for these
deficiencies the best as it can but usability suffers.
As far as performance goes, there is, of course, a penalty to pay for the
translation of 5250 screen buffers into HTML. As you can imagine, there are very
few clues in the screen buffer to indicate how fields should be translated into
HTML. A brute force method is used to figure this out and it takes some time.
The result is that response time for a browser using the gateway is several
times greater than an equivalent 5250 terminal connection.
The 5250 workstation gateway does provide some capabilities not available to
5250 terminals. One is the capability to define HTML keywords in the display file
DDS specification. A new DDS keyword (″HTML″) can be added to a DDS
specification and is recognized by the gateway. These can be used to define, for
example, HTML image tags to display graphics or a special page title, headers,
footers, and so on.
Another unique capability of the 5250 gateway is the ability for the browser to
specify the program it wants to run as part of the URL. An exit program (written
by the customer) receives this request, verifies the client′s authority to the
program, and allows the operation to take place. This eliminates the need to
present the sign-on display to the browser user and force the user to navigate to
the program the user wants to run. It makes for much better integration with
other HTML documents.
The 5250 workstation gateway is a novel approach to providing legacy
application access from the Web. It provides the AS/400 system with a
differentiator that most systems today cannot offer.
2.8.2 ″On-the-Fly″ Translation versus the Toolkit Approach
The on-the-fly approach is what WSG currently uses. It involves intercepting the
5250 data stream and trying to figure out dynamically:
1. What the green screen layout was intended to be
2. How to best represent that with HTML controls (or, in the future, Java
controls)
This is a compute intensive process and leads to a lowest common denominator
approach whereby the resulting HTML window does not look too much different
from the intended ″green screen″.
An alternative approach to this problem is being done by at least two of our
business partners, Seagull and CST. They use a toolkit approach that translates
all the windows for a particular application ahead of time rather than on-the-fly.
The toolkit allows a customer or application developer to run through all of the
windows of an application one-by-one. The toolkit does its best to translate the
5250 screen into an HTML or Java equivalent and shows the user the result. At
that time, the user can change the translated look of that window by moving,
modifying, or adding controls. The changes are recorded and the GUI
representation of that 5250 screen is stored in a separate data store and indexed
through a hash of the 5250 screen. This sequence is done for every window that
can be produced by that particular application (which could be hundreds).
Chapter 2. Internet Application Design Considerations
23
At run time, gateway code intercepts the 5250 data stream, builds a hash from it,
and uses the hash to look up the associated GUI representation of that window.
This pre-built GUI is sent to the client (browser or Java applet). If no index
exists for this hash, an on-the-fly representation of the 5250 screen is built.
This approach has the advantage of being faster at run time and provides a
more complete and tailorable GUI representation than what can be done simply
on-the-fly. However, it does require someone (typically the application provider)
to go through each window ahead of time and build the associated data store. If
changes are made to the application or the DDS, portions of the data store must
be rebuilt. Most likely, a separate data store has to be built for each
translatable version of the application.
There are definite advantages and disadvantages to each approach and you
have to decide which you want to invest in.
2.8.3 Telnet and Client Access - Personal Communication
Using a Telnet session is not really a programming model by it′s own, but might
be acceptable for many customers to allow direct access to their applications
from the Web.
However, there is no security available today to preclude others from seeing
entered USERIDs and passwords and all data flows clearly over the net (no
encryption for Telnet available today).
The same is true for Personal Communication of Client Access/400, although it
has some nice features that distinguish it from using plain Telnet (tn5250).
Personal Communication allows you to copy and paste between an AS/400
session and any other PC-session, allows you to record and playback
keystrokes, transfers files between the host and the PC, and some more
functions to assist a workstation session configuration and customization.
2.9 HTML Programming Considerations
The following sections do not try to teach you how to program HTML, but rather
give some basic information and some hints on writing HTML.
We strongly recommend that you buy one of the many available books on the
market about HTML and Web Publishing.
Note
A good reference book and book to learn about HTML is:
Teach yourself Web Publishing with HTML 3.x from Laura Lemay published by
sams.net.
There are a lot of nice HTML tools available that makes HTML coding easy, in
fact, so easy that you do not even have to do know about any HTML statement.
All of it is done through templates and prepared forms and wizards.
Because of this, there is no need to learn all about HTML, but the is no harm in
knowing about the basics. The following section gives you an introduction to
HTML and some references to more detailed information.
24
Unleashing AS/400 Applications on the Internet
2.9.1 Hypertext Markup Language (HTML)
The Hypertext Markup Language (HTML) is a simple markup language used to
create hypertext documents that are platform independent. HTML documents
are SGML (Standard Generalized Markup Language) documents with generic
semantics that are appropriate for representing information from a wide range of
domains. SGML is an international standard for document markup conforming to
ISO 8879.
The latest defined version of HTML is HTML3.2.
The major enhancements of HTML3.2 over HTML2.0 are:
•
•
•
•
Split large documents across multiple servers.
Support for tables
Support for mathematical formulae
Frame Support
HTML is similar to a computer programming language without being a
programming language. There are commands called tags and syntax rules to be
observed when writing in HTML.
HTML documents can be written using any word processor or text editor. The
way they look when seen with a Web browser, however, is quite different from
what the writer sees when editing them. It is not a What You See Is What You
Get (WYSIWYG) approach. There are HTML editors currently available on the
market that can be helpful and productive to use when writing your HTML
documents.
HTML language provides support for the following features:
•
•
•
•
Hypertext links to resources (documents, multimedia, or data files)
Menu and forms
Inline graphics
Text formatting
2.9.2 The HTML Document Structure
The HTML documents are composed of two main parts.
A head
Every document should start with a head. The head is the top part of
the document. In general, it includes the document title. Why is it,
then, important to define the head part in the document?
The different browsers on the market have different ways to display
the document′s title. The title is also the way by which documents
are referenced when saved in the Hotlist or Quicklist of the browser.
The title, therefore, must be descriptive but short so it fits into one
line of the Quicklist window.
The head of a document cannot contain anchors, any kind of
highlighting, or paragraphs. The tags to enclose the head are <HEAD>
and </HEAD> (simply meaning start and end of head).
A body
The body is the core part of the HTML document. It contains all of the
information that is part of the document and controls the way this is
presented to browser users.
Chapter 2. Internet Application Design Considerations
25
The body can contain images, lists, menus, entry fields, plain text, or
link to other resources. The tags to enclose the body are <BODY> and
</BODY> (simply meaning start and end of body).
Figure 7 shows an example of an HTML document.
<HTML>
<HEAD>
<TITLE>Ordering an AS/400</TITLE>
</HEAD>
<BODY>
<IMG ALIGN=middle SRC=″file:///htmldoc/as400.gif″>
<B>PLEASE FILL IN THE FOLLOWING :</B>
<P>
<FORM METHOD=″GET″ ACTION=″ / QSYS.LIB/HTML.LIB/ORDAS400.PGM″>
Name:
<INPUT TYPE=″TEXT″ NAME=″NAME″ SIZE=″30″ MAXLENGTH=″40″>
<P>
Address:
<TEXTAREA NAME=″ADDRESS″ ROWS=2 COLS=30>
</TEXTAREA>
<P>
<B>Which AS/400 would you like to order ?</B>
<BR>
<INPUT TYPE=″RADIO″ NAME=″P1″ VALUE=″P1″>Portable
<INPUT TYPE=″RADIO″ NAME=″P1″ VALUE=″P2″>Server
<INPUT TYPE=″RADIO″ NAME=″P1″ VALUE=″P3″>System
<P>
<B>Do you want the Support Line Service ?</B>
<BR>
<INPUT TYPE=″CHECKBOX″ NAME=″w1″ VALUE=″w″>Yes
<INPUT TYPE=″CHECKBOX″ NAME=″w2″ VALUE=″f″>No
<P>
Thanks for ordering
<INPUT TYPE=″SUBMIT″ VALUE=″Order″>
<INPUT TYPE=″SUBMIT″ VALUE=″More Information″>
<INPUT TYPE=″SUBMIT″ VALUE=″Cancel″>
</FORM>
</BODY>
</HTML>
Figure 7. HTML Document
If the HTML document is displayed with a browser, for example, Web browser for
OS/2, you see that the title in the head part is displayed in the title bar of
Figure 8 on page 27.
26
Unleashing AS/400 Applications on the Internet
Figure 8. HTML Document Displayed Through an OS/2 Web Browser
2.9.3 HTML Syntax
Let′s give you an introduction to the HTML syntax in short terms. The HTML
language consists of markup tags to identify the elements of the document. All
tags begin with a left angle bracket (<) and end with a right angle bracket (>).
Almost every tag is a container. This means that there is always an opening tag
and a closing tag the same as in the head and body. Table 1 lists the main
HTML elements:
Table 1 (Page 1 of 3). HTML Main Elements
Name
Opening tag
Closing tag
Description
Anchor
< A >
</A>
HyperLink to a resource.
Address
<ADDRESS>
</ADDRESS>
Format an address.
Bold
< B >
</B>
Display test in bold.
Base
<BASE>
No closing tag
Record URL of
document.
Body
<BODY>
</BODY>
Contain the document′ s
body.
Blockquote
<BLOCKQUOTE>
</BLOCKQUOTE>
Include text in quotes.
Line Break
<BR>
No closing tag
Break current line.
Citation
<CITE>
</CITE>
Specify a citation.
Code
<CODE>
</CODE>
Enclose an example of
code.
Chapter 2. Internet Application Design Considerations
27
Table 1 (Page 2 of 3). HTML Main Elements
28
Name
Opening tag
Closing tag
Description
Definition
list
description
<DD>
No closing tag
Description of Definition
list item
Directory
List
<DIR>
</DIR>
Enclose a directory list.
Definition
List
<DL>
</DL>
Enclose a list of terms
and definitions.
Definition
list item
<DT>
No closing tag
Item of definition list
Emphasis
<EM>
</EM>
Emphasize enclosed text.
Form
<FORM>
</FORM>
Define form of enclosed
text.
Level 1
heading
<H1>
</H1>
Enclose level 1 heading.
Level 2
heading
<H2>
</H2>
Enclose level 2 heading.
Level 3
heading
<H3>
</H3>
Enclose level 3 heading.
Level 4
heading
<H4>
</H4>
Enclose level 4 heading.
Level 5
heading
<H5>
</H5>
Enclose level 5 heading.
Level 6
heading
<H6>
</H6>
Enclose level 6 heading.
Head
<HEAD>
</HEAD>
Define the head of the
document.
Horizontal
Rule
<HR>
No closing tag
Insert horizontal line.
HTML
<HTML>
</HTML>
Define HTML document.
Italics
< I >
</I>
Italicize enclosed text.
Image
<IMG>
No closing tag
Embed an image.
Input
<INPUT>
</INPUT>
Display entry field.
Index
<ISINDEX>
No closing tag
Define searchable URL.
Keyboard
<KBD>
</KBD>
Indicate user typed text.
List item
<LI>
No closing tag
Item of Directory list,
Menu list, Ordered list,
Unordered list
Link
<LINK>
No closing tag
Describe relationship
between documents.
Menu
<MENU>
</MENU>
Enclose a menu list.
Ordered
List
<OL>
</OL>
Enclose an ordered list.
Option
<OPTION>
No closing tag
Indicate one choice in a
Select menu.
Paragraph
<P>
< / P > (optional)
Define a paragraph.
Unleashing AS/400 Applications on the Internet
Table 1 (Page 3 of 3). HTML Main Elements
Name
Opening tag
Closing tag
Description
Pre-formatted < P R E >
text
</PRE>
Enclose pre-formatted
text.
Sample
<SAMP>
</SAMP>
Indicate sample text.
Select
<SELECT>
</SELECT>
Define a set of selectable
options.
Strong
Emphasis
<STRONG>
</STRONG>
Strongly emphasize text.
Title
<TITLE>
</TITLE>
Define document′s title.
Typetype
<TT>
</TT>
Display enclosed text in
monospaced font.
Textarea
<TEXTAREA>
</TEXTAREA>
Enclose a text area.
Underlined
< U >
</U>
Underline text
(unsupported by Mosaic).
Unordered
List
<UL>
</UL>
Enclose an unordered
list.
Variable
<VAR>
</VAR>
Indicate a variable.
HTML tags are case insensitive. Every command is interpreted by the browsers
independently of the capitalization. The tag: <FORM> , for example, can either be
written: <Form> or <form> or <fORm> without making any difference.
Note This!
If you want to know more about the Hypertext Makeup Language (HTML),
there is a lot of information available on the Internet. There are also a lot of
publications available. One of them is the redbook, Using the Information
Super Highway , GG24-2499.
The most commonly used HTML tags are the headings, list, anchors or links,
images, and form tags.
The form tag is used when requesting CGI programs as we shall see in
Chapter 3, “Common Gateway Interface (CGI-BIN) Implementation” on page 57,
and the image tag is, as it says, used when referring to images or clickable
images. See Section 2.10, “Server Side Imagemap Support” on page 30 for
more information.
2.9.4 Creating Static HTML Pages
The best approach is to create all the static HTML pages with a PC tool (there
are many available on the market - check on the Internet) and store them when
you are finished on the AS/400 system in a folder, or even better yet, in the
Integrated File System (IFS).
For more information about IFS, refer to the 2.13, “IFS - Integrated File System
Considerations” on page 43.
Chapter 2. Internet Application Design Considerations
29
Note
For more detailed information about HTML coding and use, see:
http://www.ncsa.uiuc.edu/General/Internet/WWW/HTMLPrimer.html
2.9.5 Feedback
It is recommended that on your Web site, you include an e-mail address or point
of contact for your company. This allows you to gain valuable feedback, or
provide a means for users to report error conditions. For example, the following
note might appear at the foot of your home page:
Contact [email protected] with comments.
The HTML used in this example is:
Contact <A SUBJECT=″Comment on site home page″
HREF=mailto:[email protected]>[email protected]</A>
with comments.
The mailto action in the HREF tag causes the client′s e-mail package to be
opened with the subject field already filled with the text “Comment on site home
page”.
2.10 Server Side Imagemap Support
Suppose you want people to be able to choose a car, check if a certain model is
available, and make reservations from your Web server. What would be better
than to show them a map of the country and allow them to click on any location
and make the desired reservation? That is what a clickable image map can do.
It can have many other uses also. For example, it helps users better understand
a picture or diagram by allowing them to click on a component represented in
the graphic to see an explanation. It also lets users move down to finer levels of
detail on a map of a campus, building, or whatever you want.
Clickable image maps obviously work only with graphically-oriented Web
browsers. You should always try to provide alternate text-based methods of
accessing the same information.
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Unleashing AS/400 Applications on the Internet
Figure 9. Clickable World Map. This figure shows a clickable map and an alternate
text-based method of accessing the same information.
Image map requests are another form of program call or CGI. You can request
image maps from either a server-provided image mapping program or a
user-provided image mapping program. The way to provide this level of function
for your Web application is to take advantage of a server-provided mapping
program such as the one found on the AS/400 system. This IBM written CGI-BIN
application is called QTMHIMAG in the QTCP library.
If an image map request is made from a user-provided image program, it is
handled as a standard program call request that must meet the CGI interface.
There are several steps you need to take when creating a server-provided image
map:
•
Plan a clickable image map.
•
Map the hotspots in a map file.
•
Reference your clickable image map in HTML.
•
Configure the HTTP server.
Let′s take a look at each of these steps in detail.
2.10.1.1 Planning the Clickable Image Map
First, determine the image you are going to use. As for any inline images, the
graphics need to be in GIF or JPEG format for widest portability.
Define where you are going to map the clickable areas or hotspots.
Depending on the size and make up of the image you are mapping, you can use
polygons, rectangles, or circles to identify hotspots.
Chapter 2. Internet Application Design Considerations
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2.10.1.2 Mapping the Hotspots in a Map File
The next step is to develop an image map file such as the one seen previously.
You need to create a separate image map file for each clickable image map on
your Web server. Each line in an image map file represents a hotspot by
defining an area within the graphic and the corresponding URL to be returned if
someone clicks on that area with their Web browser. By using a program on
your PC such as MAPEDIT, hotspots on the image are formatted by:
Shape, Coordinate-1, Coordinate-2 ... Coordinate-n, URL.
Figure 10. Defining Hotspots and Associated URLs.
circle shape mapped to its associated URL.
This figure shows North America in a
This map is made up of circles and triangular shaped polygons. A rectangular
shape was mapped last for the entire image as a default area.
Hotspots are defined by the following shapes:
•
A circle - for a circle (a pair of coordinates for the center and a single value
for the radius).
•
A polygon - for a polygon (the number of coordinates depend on the number
of sides defined for the polygon).
•
A rectangle - for a rectangle (with two coordinate pairs: upper-left and
lower-right).
Coordinates are x,y pairs counting in pixels from the upper left-hand corner of
the image. The URL can be either an actual URL pointing to any resource on the
World Wide Web, or it can point to another image or document on your server.
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Unleashing AS/400 Applications on the Internet
001.00
002.00
003.00
004.00
005.00
006.00
007.00
008.00
*************** Beginning of data ********************************
circle (101,123) 42 /ITSOIC.400/imvh301.htm#SAMERICA
circle (56,46) 45 /ITSOIC.400/imvh301.htm#NAMERICA
circle (180,98) 41 /ITSOIC.400/imvh301.htm#AFRICA
circle (265,50) 47 /ITSOIC.400/imvh301.htm#ASIA
poly (218,10) (215,58) (138,49) /ITSOIC.400/imvh301.htm#EUROPE
poly (346,68) (184,170) (347,170) /ITSOIC.400/imvh301.htm#OCEANIA
rect (4,3) (351,177) /ITSOIC.400/imvh301.htm#OCEANIA
default /ITSOIC.400/imvh301.htm#OCEANIA
****************** End of data ***********************************
Figure 11. Image Map Coordinates. This example shows circular, polygon, and
rectangular shapes and their defined URLs.
The server takes the coordinates from a user′s mouse click and steps through
the map file to determine if the click is within any hotspots. As soon as the first
match is found, the corresponding URL is used to redirect a document to the
user′s Web browser. If no matches are found, a default URL (that you specify in
the image map file) is returned.
Notice that the last line in the file is a default statement. This might be helpful
so that if a user clicks on a part of the image that has not been mapped, the
user is sent to a defined default area.
It is normal to mix and match circles, polygons, and rectangles in the same map
file. Although you should try to minimize overlapping hotspots in the image
map, if there are any, the first match is the one used.
2.10.1.3 Referencing Your Clickable Image Map in HTML
The final step in creating an image map is to tell the Web browser accessing the
HTML document that the inline image it displays is a clickable image map. In
practice, what you do is create a link where this image is the link trigger and the
URL invokes the image map script and passes it the map name. For example:
<A HREF=″http://servername/imagemap.pgm/imagemap.file″>
<IMG SRC=″image.gif″> ISMAP></A>
2.10.1.4 Configuring Your Clickable Image Map in the HTTP Server
To configure the HTTP server on the AS/400 system, we reference the previous
example. Our imagemap.pgm is qtcp/qtmhimag and our image maps are found in
the imagemap.file. Here is how our URL looks using the AS/400 system to serve
image maps:
<A HREF=″http://servername/qsys.lib/qtcp.lib/qtmhimag.pgm1
/qsys.lib/itsoic400.lib/imagemap.file/mapk.mbr″>2
<IMG SRC=″imvg300.gif″ ISMAP></A>3
1
This section of the URL represents the server name and also where the
image mapping program resides on the AS/400 system.
2
This section tells the server where the actual image map file is located
on the AS/400 system.
3
This section shows the source of the image or GIF file that is to be
mapped and ISMAP tells the server this is an image map.
We can shorten and simplify the URL by taking advantage of the HTTP mapping
rules. For example, we use the following URL to do the same thing:
Chapter 2. Internet Application Design Considerations
33
<A HREF=″ / cgi-bin/imagemap/map1.mbr″>
<IMG SRC=″world.gif″ ISMAP></A>
Where you see /cgi-bin/imagemap, we used the HTTP Map configuration statement
to reference the longer URL. The following lines must be added to the HTTP
configuration to make it work:
Map /cgi-bin/imagemap/* /qsys.lib/qtcp.lib/qtmhimag.pgm
/qsys.lib/itsoic400.lib/imagemap.file/*
Pass /qsys.lib/itsoic400.lib/imagemap.file/*
Exec /qsys.lib/qtcp.lib/*
To access the HTTP configuration file, type WRKHTTPCFG on an AS/400
command line. Add the Map, Pass, and Exec statements noted previously. By
using the Map directive in our HTTP configuration, we are able to use shorter
URLs in our HTML documents. The Pass statement is there to pass the image
map files from the server. There must also be an Exec statement to call the
qtmhimag program from the qtcp library.
Figure 12. Mapping of Image Map URL to HTTP Configuration
Note
More information on image mapping and image map requests on the AS/400
system is available in the TCP/IP Configuration and Reference, Version 3 ,
SC41-3420.
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Unleashing AS/400 Applications on the Internet
2.10.2 Server Side Image Maps Considerations
More and more browsers do support client side image maps today, so the
urgency for providing this on the server is almost gone. However, a server such
as the AS/400 system, especially some of the faster server models (50S, 53S),
can provide a much faster solution for image maps than a typical PC can do. On
the other hand, if there are many of these kinds of requests, the server is quite
busy doing these operations and it might be worthwhile to move this to the
browsers.
2.11 Netscape, Microsoft IE, IBM Web Explorer, Spyglass
Currently the most popular browser for the World Wide Web is Netscape′ s
Navigator developed by Netscape Communications Corporation. Netscape has
become so popular that using Netscape and using the Web have become
synonymous to many people. However, despite the fact that Netscape has the
lion′s share of the market, it is not the only browser on the Web.
It is important for you as an Internet application programmer to make a
distinction between the information on the Web and the browser used to view it.
Assuming Netscape is the only browser in use on the Web, designing your pages
accordingly limits the audience you can reach with the information you want to
present.
A wide array of Web browsers is available for just about every platform you can
imagine, including graphical user-interface based systems (Mac, Windows, X11)
and text-only for UNIX dial-up UNIX connections. Most browsers are freeware or
shareware (try before you buy) or, the same as Netscape, have a lenient
licensing policy (Netscape allows you to use its browser for personal use for an
evaluation time after which you are expected to buy it). Usually all you have to
do is download them from the net. If you get your Internet connection through a
commercial online service such as America Online or CompuServe, there are
usually Web browsers built into the software for that system as well.
Although we urge the application programmer to consider the differences of
browsers, we advise the programmers to design their applications to be
independent from browsers as much as possible. That means, stay away from
specific functions available only on some browsers (although they might have
real nice functions).
2.12 ILE Integrated Language Environment Programming Considerations
This section concentrates on aspects of the ILE architecture that must be
addressed from a design perspective. The contents should be read by anyone
involved in either designing migrations from Original Program Model (OPM) to
ILE or designing new ILE applications.
2.12.1 Overview of ILE Concepts
ILE provides new concepts to support both a run-time environment with fire walls
built around an application and a development environment supporting the
production of highly modularized, reusable code. These new concepts are
summarized later. For full details of each of these facilities, please refer to
Integrated Language Environment Concepts , SC41-3606.
•
Procedures
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35
A procedure is a set of self-contained HLL statements that perform a
particular task and return to the caller. In ILE RPG/400  and ILE CL, there
is one procedure per source member and one procedure per module. The
procedure name is always the same as the containing *MODULE name for
RPG IV and ILE CL. In ILE C/400 there may be multiple procedures (called
functions in C) within a module. Refer to Program Entry Procedure on page
38 for this special form of a procedure.
•
Modules and programs
A module object (*MODULE) is the result compilation using the new ILE
compile commands. A module cannot be run. To be run, a module must be
bound into a program object (*PGM).
An ILE program object (*PGM) is the result of binding one or more modules
together. You run programs on the system just as you did in OPM.
•
Static binding
In OPM, all calls to programs are dynamic, involving system overhead to
perform authority checking and find the address of the program. Binding is
the process of creating a program by packaging ILE modules and resolving
symbols passed between those modules.
When a dynamic call is made to an ILE *PGM object, the program is
activated. This activation involves the initialization of all static storage
required by variables used by the modules within the object. In the case of
RPG IV, all variables are stored in static storage.
There are two types of static bind available within ILE. Once a program and
any related service programs have been activated, there is no difference in
the system code that is run to perform a bound call by reference or a bound
call by copy.
1. Bind by copy
This is the process of copying modules directly into a program object
during the binding phase. Thus, the modules specified to be bound by
copy are contained directly within the program object.
2. Bind by reference
This is the process of making procedures indirectly available to a
program (*PGM) through a service program (*SRVPGM). Modules bound
in a *PGM by reference to a *SRVPGM are not copied into the *PGM
object.
Optional service programs (*SRVPGMs) is associated with the *PGM at
bind time. The activation of these associated service programs involves
the initialization of all static storage in all modules within the service
programs.
•
Service Programs
Service programs cannot be run through a dynamic call. They act as a
container for related procedures that are used in many different *PGMs.
Thus, in order to easily maintain these popular procedures, they are stored
in one place, a service program.
Since activation of a *SRVPGM causes initialization of all static service
programs, it involves the initialization of all static storage in all modules
within the service programs. Even if your *PGM only uses one module from
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Unleashing AS/400 Applications on the Internet
a service program, if the service program contains N>1 modules, the static
storage for all N>1 modules is initialized at activation of your *PGM.
•
Binding Language
This is a simple language that controls which procedures and variables are
available from a service program to other programs or other service
programs.
•
Activation Groups
An activation group enables partitioning of resources within a job.
Therefore, an activation group is only seen by the job in which it was
created. An activation group consists of static storage needed for variables
belonging to activated programs, open files (open data paths), commitment
control definitions, and application programs. When a new job is started, the
system automatically creates two activation groups. These are collectively
referred to as the default activation group but are split into activation group
number 1 and number 2.
All programs (system or user) run in an activation group. The activation
group in which an application program runs is determined at program
creation. When you create ILE programs and service programs, you specify
the activation group in which your program runs using the ACTGRP keyword.
You can choose one of the following options:
1. NAMED activation group
An activation group with a name you specified at the time of creating ILE
programs.
2. *NEW activation group
Every time the program is dynamically called, a new activation group is
created. As soon as the program returns control to its caller, the *NEW
activation group is deleted. Frequent use of this choice provides the
worst performance within your application.
If You Want ANSI Semantics...
Activation group of anything other than *NEW may result in the
program′s run-time behavior not following ANSI C semantics.
3. *CALLER activation group
The program is run in the activation group of its calling program.
•
ILE Program Activation
When a dynamic call to an ILE program is issued within a job, the system
performs the following tasks known as program activation:
1. Identify what activation group the *PGM should run in.
If the activation group is NAMED and does not exist, create it. If the
activation group is *NEW, create a new activation group in which to run
the *PGM (this is expensive in terms of CPU). If the *PGM has not been
called in this activation group before (always the case with *NEW
activation groups), initialize all static storage for all associated modules
whether they are bound by copy or bound by reference.
2. Activate all service programs that have been bound to the *PGM.
Identify which activation group the *SRVPGM should run in.
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If the activation group is NAMED and does not exist, create it. If the
*SRVPGM has not been called in this activation group before, initialize
all static storage for all modules in the service program.
3. Pass control to the Procedure Entry Point (PEP) in the first procedure
specified in the MODULE list at *PGM creation time.
4. If the entry procedure is RPG IV without using the logic cycle, control
passes to the first executable statement in the calculation specifications
after full opens of required files and resolution of passed parameters
exactly as in OPM.
When the program is deactivated and it runs in a *NEW activation group,
the activation group is deleted and all associated resources are returned
to the system.
•
Binding Directory
A list of modules or service programs. The contents of a binding directory
are only used by the binder if unresolved imports exist during either the bind
of modules specified on the MODULE list or modules exported from service
programs specified on the BNDSRVPGM list.
•
Program Entry Procedure (PEP)
A PEP is system generated and the first procedure placed on the call stack
following a dynamic call. This procedure is always given control first
following a dynamic call. The PEP ensures that the procedure you specified
as the Entry module on the CRTPGM is given control following a dynamic
call.
Service programs never have PEPs on the call stack. This is because any
procedure in a bound service program may be called (multiple entry points
(MEP)); there is no concept of a first procedure to always be run (PEP) in a
service program. (Remember that service programs cannot be run by a
dynamic call.) The name of the PEP on the call stack depends on the ILE
HLL used for the entry module (ENTMOD) of the program. These names are:
_C_pep for ILE C
_Q_QRNP_PEP for ILE RPG/400
_CL_PEP for ILE CL
2.12.2 ILE Compile and Bind Commands
There are two categories of ILE compile commands provided:
1. Full-function ILE compile and bind commands:
The Create Module command and Create Program command provide access
to all of the features available within ILE. Greater design flexibility is
provided as a result of splitting the compile and bind into two separate
commands. The Create Module commands are used to compile a module
object, hence the command is ILE compiler-dependent. CRTRPGMOD is
used to create an RPG IV module and CRTCLMOD is used to create an ILE
CL module. To obtain an executable *PGM object within ILE, it is necessary
to perform a compile of source code into a module object (*MODULE)
followed by a bind of the *MODULE object (or objects) into a program object
(*PGM). Either the Create Program (CRTPGM) command is used to bind
*MODULE objects into a program, or the CRTBNDxxx command is used to
perform a one step compile-and-bind to create a program.
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Unleashing AS/400 Applications on the Internet
The Create Service Program (CRTSRVPGM) is used to bind modules into a
service program object. As previously stated, you cannot directly run a
service program; you can only indirectly run procedures in a service
program through bound calls from the *PGM object that was created with
references to the service program.
2. Restricted ILE compile and bind commands:
The Create Bound Program commands CRTBNDRPG and CRTBNDCL
provide access to some but not all of the ILE facilities. Thus, these
commands are designed to be simple to use and, consequently, do not
provide the flexibility of the full-function ILE commands. Use of these
commands enables you to take advantage of RPG IV. If you elect to run in
OPM compatibility mode, you cannot use the call bound (CALLB) operation
code; the compile part of the process fails with the following message:
RNV5378 severity 30 CALLB cannot be used when DFTACTGRP(*YES) is specified
for CRTBNDRPG If you specify DFTACTGRP(*YES), your program is only run in
the default activation group; hence, you are unable to take full advantage of
ILE named activation groups and resource scoping.
2.12.3 OPM Compatibility Mode
Compatibility mode is an ILE program attribute that, when enabled, makes an ILE
program behave in a manner compatible with OPM program behavior. This
facility is available for the ILE RPG/400 and ILE CL programming languages; it is
not available for ILE C/400.
The way to enable OPM compatibility mode for an ILE program is to use the
CRTBNDRPG or CRTBNDCL command and specify DFTACTGRP(*YES).
Use this command if you want to migrate all or part of your application from RPG
III to RPG IV, but you do not want to take advantage of ILE bound calls, service
programs, or activation groups at this time.
If you enable compatibility mode (specify DFTACTGRP(*YES) on the CRTBNDxxx
command), the following ILE facilities are not available to you:
1.
2.
3.
4.
Bound calls
EXPORT/IMPORT keywords and specifications
Service programs
Use of named or *NEW activation group
2.12.4 Activation Groups
All OPM programs run in the same activation group (the system-provided default
activation group).
Within ILE, activation groups are used to logically partition applications that are
used concurrently within the same OS/400 job. Activation groups exist for the
life of the job that created them. Once the job is terminated, all activation
groups associated with that job are deleted.
Creation of a new ILE program or service program always involves the
specification of the activation group in which the program runs. Thus, resources
such as the order entry (OE) and accounts receivable applications are separated
such that there is no conflict over files common to both applications,
commitment control scoping, and variables used within programs common to
both applications.
Chapter 2. Internet Application Design Considerations
39
This separation of applications and application resources within a job is
implemented in ILE through the use of activation groups.
2.12.4.1 Default Activation Group
OPM programs and ILE programs created with OPM compatibility mode always
run in the default activation group. Specifically, these programs always run in
default system activation group number 2, which is the user-portion of the default
activation group available for your applications to use.
2.12.4.2 User-Named Activation Group
Upon a dynamic call to an ILE program that specifies a named activation group,
if the activation group does not already exist within the job, it is created. An
important difference between named activation groups and the other types of
activation groups is that a new activation group is only deleted when the
Reclaim Activation Group (RCLACTGRP) command is issued.
Specify the name of an activation group using the ACTGRP keyword on the
CRTPGM or CRTBNDxxx commands.
Named Activation Group...
You do not want to populate a table with activation groups. They should be
used by heavy-duty applications that require significant startup costs.
2.12.4.3 Activation Group of Caller
We expect that most ILE programs are created to run in the same activation
group as their calling program. To specify this, you should use
ACTGRP(*CALLER) on the CRTPGM command. Control of where your program
is run is determined by the application start-up program or programs that
explicitly specify your application′s activation group name.
You can also specify that an ILE service program be run in the same activation
group as the ILE program to which it is bound by using the default of
ACTGRP(*CALLER) on the CRTSRVPGM command.
2.12.4.4 System-Named Activation Group (*NEW)
This is the default on the CRTPGM command, and is deliberately not available
on the CRTSRVPGM command. Whenever a program created with
ACTGRP(*NEW) is called dynamically, a new activation group is created, the
program is activated and run, and when the program returns control to its caller
(through RETURN, LR, or a hard leave), the activation group is deleted.
IMPORTANT
Avoid using ACTGRP(*NEW) even though it is the default on CRTPGM. Using
this activation group option is the worst choice for performance.
We recommend that this option is not used within an ILE application. It is
expensive in terms of system resource to keep creating and deleting *NEW
activation groups.
We recommend that you run ILE programs in a named activation group rather
than allowing them to run in the default activation group.
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Unleashing AS/400 Applications on the Internet
2.12.5 Activation Group Recommendations
Application start-up program or programs should be created to run in NAMED
activation group or groups such that programs subsequently called can safely
specify ACTGRP(*CALLER). Since activation group names can only be changed
by re-creating the program, this approach minimizes your effort in case of a
change.
Consider changing the default value to *CALLER using the Change Command
Default (CHGCMDDFT) command.
Your application design should ensure that ILE programs created with
ACTGRP(*CALLER) are not called from the default activation group. When an ILE
program is run in the default activation group, its files may be closed by the
RCLRSC command. The RCLRSC command may be issued by some other
application running in the default activation group and, therefore, outside the
control of your application.
When an ILE program is run in a named activation group, its files may only be
closed by the RCLACTGRP command or by the use of the RPG IV SETON LR
operation just as it functions today for OPM.
2.12.6 Differences Between Default and Non-Default Activation Groups
Any ILE application design must consider whether programs should be allowed
to run in the default activation group or not.
The cause for an ILE program running in the default activation group is ONE of
the following reasons:
•
The program was created with the ACTGRP(*CALLER) attribute, and its caller
is running in the default activation group.
•
The program is running in compatibility mode.
The default activation group is provided for running OPM programs and ILE
programs with OPM compatibility mode. You should not design new ILE
programs to run in the default activation group; for a new application you should
use a named activation group.
We now summarize the main differences between running an ILE *PGM created
with ACTGRP(*CALLER) (thus not created with OPM compatibility mode) in the
default activation group versus running it in a non-default activation group (for
example, user-named or *NEW).
1. Exception handling
If you do not handle exceptions in your application, an extra CEE9901
message is generated when you run the *PGM in the default activation
group.
2. Scoping
OVRSCOPE and OPNSCOPE on the OVRDBF and OPNDBF commands default
to *ACTGRPDFN. Thus, when you open your files as SHARE(*YES), the file is
opened scoped to the call level in the default activation group; it is opened
scoped to the activation group level in a non-default activation group.
3. RCLRSC
Chapter 2. Internet Application Design Considerations
41
This command cannot be run in a non-default activation group. It causes
files to be closed for ILE procedures run in the default activation group. This
command also works differently for ILE compatibility mode programs to ILE
non-compatibility mode programs.
4. Static Storage
All RPG variables are kept in static storage. Once an ILE procedure has
been run in the default activation group, the static storage associated with its
variables are not returned to the system until end-of-job (the program is not
deactivated until end-of-job).
2.12.7 Migration to ILE from the Original Programming Model
To take advantage of the enhancements provided with the RPG IV language
definition, you might consider converting your existing RPG application. As you
can appreciate, RPG IV gives you more flexibility and better readability, and as a
result of these advantages, you can improve your development environment and
productivity.
An important point is that the new design of RPG IV opens the door for future
enhancements and functions that were impossible to implement on the previous
compiler. The reason was the restrictions in the layout on the different
specifications statements. Increasing the length for some of the entries,
introducing keywords, and free format operations in the extended calculation
specifications lifted these limitations.
IBM offers you a simple control language command to convert your RPG/400 or
RPG III source members to RPG IV source members.
Before you start migrating your RPG source members, you might want to create
a new source file to store the RPG IV sources. The default name for the RPG IV
source file is QRPGLESRC. It is recommended that you use this name because
all of the CL commands use this name as the default when they refer to the RPG
IV source file.
When you are creating the target source file using the command CRTSRCPF for
RPG IV members, specify 112 for record length. Twelve characters are for
sequence numbers and date fields. The additional 100 characters receive your
source code. The length of the statement field has been increased to include the
new size of the entries in the specifications layouts. If you leave the default size,
you lose the commenting text entries.
If you are using variant characters in your program, make sure that the CCSID of
the source file is specified correctly. The CCSID of a new source file created on
V3R1 is taken from the default CCDID job attribute unless a CCSID is specified
on the CRTSRCPF command.
There is also a new source type, RPGLE. The SEU and PDM recognize the new
type as an RPG IV source. If the source type is RPGLE, SEU performs the
appropriate syntax check for RPG IV statements.
In the Work with Members Using PDM display, there is a new option (15=Create
module). Using this option, if the source type is RPGLE, PDM submits to job
queue to run the CRTRPGMOD command to create an ILE RPG module. Using
option 14, if the source type is RPGLE, PDM submits to job queue the
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Unleashing AS/400 Applications on the Internet
CRTBNDRPG command to create a bind RPG program with only one module.
More about these commands appears later in this chapter.
RPGLE is also the attribute type for an ILE RPG program and for module objects.
Note
The conversion command from RPG/400 to RPG IV source members
automatically renames the source type to RPGLE.
2.13 IFS - Integrated File System Considerations
This section discusses the IFS (Integrated File System) support available on the
AS/400 system. The IFS is a base support for Internet application development
on the AS/400 systems.
2.13.1 Short Overview of Various File Systems in IFS
A file system provides the support that allows users and applications to access
specific segments of storage that are organized as logical units. These logical
units are files, directories, libraries, and objects.
Each file system has a set of logical structures and rules for interacting with
information in storage. These structures and rules may be different from one file
system to another. In fact, from the perspective of structures and rules, the
OS/400 support for accessing database files and various other object types
through libraries can be thought of as a file system. Similarly, the OS/400
support for accessing documents (which are really stream files) through the
folders structure may be thought of as a separate file system.
The integrated file system does indeed treat the library support and folders
support as separate file systems. Other types of file management support that
have differing capabilities are also treated as separate file systems. The file
systems are:
″root″
The / file system.
This file system takes full advantage of the stream
file support and hierarchical directory structure
of the integrated file system.
The root file system has the characteristics of
the Disk Operating System (DOS) and OS/2 file systems.
QOpenSys
The open systems file system.
This file system is compatible with UNIX-based
open system standards such as POSIX and XPG.
Similar to the root file system, it takes advantage
of the stream file and directory support that is
provided by the integrated file system.
In addition, it supports case-sensitive object names.
QSYS.LIB
The library file system. This file system supports
the AS/400 library structure. This file system
provides access to database files and all of the
other AS/400 object types that the library support
manages. This is also the only file system where
AS/400 executable objects can be stored.
Chapter 2. Internet Application Design Considerations
43
QDLS
The document library services file system.
This file system supports the folders
structure. It provides access to documents and folders.
QLANSrv
The LAN Server file system.
This file system provides access to the same directories
and files that are accessible through the
LAN Server licensed program. It allows
users of the OS/400 file server and AS/400
applications to use the same data as LAN Server clients.
QOPT
The QOPT file system. This file system provides
access to stream data that is stored on optical media.
QFileSvr.400 The QFileSvr.400 file system. This file system
provides access to other file systems that
reside on remote AS/400 systems.
UDFS
The user-defined file system.
This file system resides on the Auxiliary Storage
Pool (ASP) of the user′ s choice. The user creates
and manages this file system.
NFS
The Network File System.
This file system provides the user with access to
data and objects that are stored on a remote NFS
server. Network file systems can be exported from
an NFS server and dynamically mounted by NFS clients.
QNetWare
The QNetWare file system.
This file system provides access to local or
remote data and objects that are stored on a server
that runs Novell NetWare 3.12 or 4.10. A user
can dynamically mount NetWare file systems over
existing local file systems.
Users and application programs can interact with any of the file systems through
a common integrated file system interface. This interface is optimized for the
input/output of stream data in contrast to the record input/output provided
through the data management interfaces. A set of user interfaces (commands,
menus, and displays) and application program interfaces (APIs) is provided for
interacting with the file systems through this common interface.
2.13.2 Which AS/400 File System Works Best?
IBM′s HTTP server can serve documents from the following file systems:
•
•
•
•
The AS/400 library system (QSYS.LIB)
QDLS
The integrated file system ″root″ directory
QOpenSys
You can also serve files from all other Integrated files systems installed on your
AS/400 system (for example, QLANSrv). However, these file systems are more
sophisticated to configure and we do not recommend them unless you have a
burning need to do so.
We cannot provide a simple answer to this question but we can give you a few
things to think about. The good news is that you are not stuck with any one file
44
Unleashing AS/400 Applications on the Internet
system. You can use a combination of file systems to apply the best solution to
each situation. The following list contains some of the primary considerations:
•
Performance is usually a primary consideration. Our tests show that in a
typical configuration, serving from the root directory is the fastest. Here are
the relative numbers (your mileage may vary):
1. Integrated File System - ″root″ directory = 1
2. Integrated File System - QOpenSys directory = 1
3. QDLS = .75
4. AS/400 file system = .45
5. QLANSrv = .22
•
Environment is also important. How do you intend to create and maintain
your HTML files? With Client Access, it is easy to move files from your PC to
a directory in the root or QDLS. You can take advantage of the cool PC tools
for maintaining HTML files. On the other hand, you can use SEU and create
your files right on a ″green screen″ terminal. It is not a lot of fun but it
allows you to utilize data entry people that are familiar with editing file
members.
•
Flexibility is an issue if you want to transport your pages from one platform
to another. A typical situation is that your boss wants to load your Web
pages on a lap top and show it off to people higher on the food chain. If you
keep file names to eight characters with three-character extensions, use
relative path names for links, and store the files in a directory structure
under the Integrated File System root, you can easily replicate the structure
on a PC. If you foresee any potential for needing to run your site in demo
mode (customer visits, trade shows, Mom and Dad come for a visit), we
highly recommend you consider the Integrated File System.
•
Applications may also affect your decision. For example, if you have a
CGI-BIN application that interacts with an HTML page, you may want to keep
that page in the same library as the program. This keeps the entire
application in one place.
We use several library systems. Most of our HTML files are in a directory
structure under the Integrated File System root (performance and file
maintenance). We keep all of our CGI-BIN programs and related HTML files
in a single library (simplify moving things from our test system to the
production server).
The following figure shows the complete Integrated File System structure.
Chapter 2. Internet Application Design Considerations
45
Figure 13. AS/400 File Systems, File Server, and Integrated File System Interface
The OS/400 file server also uses part of the Integrated File System interface.
This file server provides file serving capabilities equivalent to shared folders, but
allows PC clients to access information in any of the file systems. The PC clients
use their own interfaces to interact with the file systems rather than the
Integrated File System user interfaces and APIs.
PC clients using the LAN Server requestor or Novell NetWare requestor interact
with the Integrated PC Server (File Server I/O Processor) directly rather than the
Integrated File System interface. The Integrated PC Server provides even higher
rates of access to its files.
2.13.3 How to Exchange Data Between the Root or QOpenSys and QSYS.LIB
There are two commands available to transfer data between the AS/400 library
file system and any other IFS file system:
•
CPYFRMSTMF - Copy from Stream File
•
CPYTOSTMF - Copy to Stream File
However, you can also use your file manager in OS/2 or in Windows95 and
Client Access to copy, edit, and manage your files in the IFS on the AS/400
system.
For more information, refer to the following topics and publications:
46
Unleashing AS/400 Applications on the Internet
•
OS/400 file server:
OS/400 Server Concepts and Administration , SC41-3740
•
LAN Server:
LAN Server for OS/400 Administration , SC41-3423
•
NetWare:
OS/400 NetWare Integration Support , SC41-4124.
2.14 Java Programming Considerations
This section discusses how different Java programming techniques can further
enhance your AS/400 HTML pages.
2.14.1 Java Scripts being Served from AS/400 System
Any Java Scripts created on any platform can be stored and served from the
AS/400 system to any client requesting the script.
There are no special things to take into consideration for serving Java Scripts.
The following information is a Java Script test page found on the Internet at:
http://www.software.ibm.com/data/net.data/demos/demopage.html#jsl
This test page can be used to explore the capabilities of JavaScript and you can
copy the code and implement it into your application. Please give it a try!
Figure 14. JavaScript Library Test Page (Part 1)
Note
Although it says in the preceding text that these functions are provided with
Net.Data, these JavaScripts can be used in conjunction with CGI.bin
programs as well.
Chapter 2. Internet Application Design Considerations
47
Figure 15. JavaScript Library Test Page (Part 2)
Reference
For more Information on Java Scripts, see Chapter 6, “Further Enhancing
Your AS/400 HTML Pages” on page 221.
2.14.2 Java Applets being Served from AS/400 System
Any Java applet created on any platform can be stored and served from the
AS/400 system to any client requesting the applet.
There are no special things to take into consideration for serving Java applets.
Reference
For more information on Java Applets, see Chapter 6, “Further Enhancing
Your AS/400 HTML Pages” on page 221.
2.14.3 Java Applications being Executed on AS/400 Java Virtual Machine
A prototype of the Java virtual machine for the AS/400 system is available as a
technology preview that you can download from:
http://www.ibm.com/java/
http://ncc.hursley.ibm.com/javainfo/download/index.html
2.14.3.1 What Is a Technology Preview?
This technical preview is an early demonstration of Java technology on the
AS/400 system. It is intended to give developers a chance to ″try-out″ Java on
an AS/400 system. This technology preview is a port of Sun′s JDK 1.0.2 and can
be used for prototyping or testing Java applications on the AS/400 system. This
technology preview does not include a JIT (Just-In-Time ) compiler.
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Unleashing AS/400 Applications on the Internet
2.14.3.2 Capabilities of the Current Technology Preview
The technology preview provides run-time support for Java on the AS/400
system. Development of Java applications can be done on any Java workstation,
and be ported onto the AS/400 system without modification. Alternatively, the
javac compiler is also being made available in this release of the technology
preview. This allows the compilation of Java code on the AS/400 system.
Even though the Java byte code compiler is included in Technology Preview T1,
the recommended way to develop Java code for the AS/400 system is to create
and compile the code on a PC based client machine and transfer it to OS/400.
The best way of doing this is to use Client Access/400 because it provides an
easy way of transferring files between your client and OS/400. It also provides
the ability to use long file names in mixed case using the Integrated File System.
You cannot access the QOpenSys file system when using Client Access/400 for
Windows.
2.14.3.3 Performance
This technology preview does not include any Just-in-Time (JIT) or other
optimizing compiler technology. The performance characteristics are similar to
other initial Java offerings based on the SUN JDK 1.0.2. Furthermore, the JDK
runs on top of OS/400 and is not integrated into the operating system.
Therefore, it is expected that the performance of the Technology Preview release
of Java for the AS/400 system will be slower than what is seen on comparable
platforms with JIT compilers or other optimizing technology. But as is always
true when performance measurements are made, ″your mileage may vary″.
Performance is highly dependant on the application being run.
Read the Java for the AS/400 White Paper to learn more about planned
performance improvements.
2.14.3.4 White Paper
Reference
A white paper on Java for the AS/400 system is available that provides
information on the future strategy and direction for Java on the AS/400
system. Please see Chapter 7, “AS/400 Internet Technology Preview” on
page 225.
2.14.4 Using NetRexx to Create Java Applets
This section discusses the support provide by NetRexx for creating Java Applets.
2.14.4.1 What Is NetRexx?
IBM is actively investigating alternatives to the Java language for programming
the Java environment. The most advanced of these is NetRexx, an experimental
dialect of REXX that can be as efficient as languages such as Java while
preserving the low threshold to learning and the ease of use of REXX and Object
REXX. It is anticipated that the technology developed during the research of
NetRexx can be applied to some future version of Object REXX.
Object REXX can also play its role in network-centric computing; it is well
positioned to be used for developing so-called intelligent agents. Intelligent
agents are programs that make decisions, filter information, or obtain knowledge
for their owners based on information ranging from a simple user profile to
Chapter 2. Internet Application Design Considerations
49
complex, systematized rules and directives. Agents are especially suited for
things such as stock brokering, shopping in ″electronic marketplaces″, and other
tasks that require rummaging around networked environments.
NetRexx is a new human-oriented programming language designed as an
effective and simple alternative to the Java language. With NetRexx, you can
create programs and applets for the Java environment faster and more easily
than by programming in Java. Using Java classes is especially easy in NetRexx
as the different types of numbers and strings that Java expects are handled
automatically by the language.
Inspired by two different programming languages, Rexx and Java, NetRexx
blends the easy-to-learn syntax of Rexx with the robustness and portability of the
Java environment. The result is a language that is tuned for both scripting and
application development and is, therefore, truly general-purpose.
The initial implementation of the language is a compiler that first translates the
NetRexx source code into Java source code; a Java compiler is used to generate
the Java byte codes (class files) for execution. NetRexx classes and Java
classes are entirely equivalent (NetRexx can use any Java class and vice versa).
Initial measurements using the current implementation suggest that the Java
source for a typical class has approximately 35% more lexical tokens and
requires 20% more keystrokes than the equivalent in NetRexx.
The NetRexx compiler (NetRexxC) is written in NetRexx and should run on any
Java platform that supports the Java toolkit and compiler (javac). By default,
NetRexxC automatically calls the javac compiler to create class files but you can
use other Java compilers if you want (the generated Java source is accessible).
For samples (and examples of using Java classes from NetRexx) and for more
formal details of the language, please see the other NetRexx documents at
http://www2.hursley.ibm.com/netrexx/
You can find the NetRexx packages to download there also.
2.14.5 Using Perl to Create Java Applets
IBM and Mortice Kern Systems (MKS) have released a beta of version 5.003 of
PERL for the AS/400 system. PERL is a popular scripting language used to
create Web Common Gateway Interface (CGI) applications running on a variety
of operating systems, including UNIX, Windows 95, and Windows NT . As part
of IBM′s commitment to Web-enable the AS/400 system, IBM contracted with
MKS to port PERL to the AS/400 system.
Although IBM could charge for PERL, the original PERL authors guaranteed in
their licensing agreement that anyone can freely distribute any version of PERL
(and the PERL source code). This is a boon to users, of course, although it
usually means that once the initial port is accomplished, users are left on their
own for technical support. There are many resources available to PERL
programmers from news groups and books.
50
Unleashing AS/400 Applications on the Internet
2.14.5.1 What Is PERL?
PERL′s author, Larry Wall, describes PERL this way:
PERL is an interpreted language optimized for scanning arbitrary text files,
extracting information from those text files, and printing reports based on that
information.
It is also a good language for many system management tasks. The language is
intended to be practical (easy to use, efficient, and complete) rather than
beautiful (tiny, elegant, and minimal). It combines (in the author′s opinion,
anyway) some of the best features of C, sed, awk, and sh so people familiar with
those languages should have little difficulty with it. (Language historians also
note some vestiges of csh, Pascal, and even BASIC-PLUS.) Expression syntax
corresponds quite closely to C expression syntax. Unlike most UNIX utilities,
PERL does not arbitrarily limit the size of your data (if you have the memory,
PERL can slurp in your entire file as a single string). Recursion is of unlimited
depth. And the hash tables used by associative arrays grow as necessary to
prevent degraded performance. PERL uses sophisticated pattern matching
techniques to scan large amounts of data quickly. Although optimized for
scanning text, PERL can also deal with binary data and can make dbm files look
the same as associative arrays (where dbm is available).
Setuid PERL scripts are safer than C programs through a data flow tracing
mechanism that prevents many stupid security holes. If you have a problem that
ordinarily uses sed or awk or sh, but it exceeds their capabilities or must run a
little faster, and you do not want to write the silly thing in C, PERL may be for
you. There are also translators to turn your sed and awk scripts into PERL
scripts.
The PERL beta run time and source code is distributed as AS/400 save files and
should be available for downloading at:
ftp://ftp.cs.colorado.edu/pub/perl/CPAN/ports/as400/
The public domain software is now available for downloading that allows you to
run PERL scripts on the AS/400 system.
The PERL distribution for the AS/400 system is packaged as three SAVF format
files:
The PERL source, libraries, and test suites (perlsrc.savf) (4.3MB)
A precompiled perl executable with the PERL libraries
and test suites (perlpgm.savf) (4.9MB)
A precompiled perl executable with the PERL libraries
and test suites (perlrisc.savf) for RISC systems (9MB)
These files are available at CPAN sites in the directory: ports/as400. Please see
the installation notes and the readme which is included in the save file for
complete unpacking and installation instructions and any known problems and
limitations.
Note:
This is public domain software.
Chapter 2. Internet Application Design Considerations
51
IBM does not provide service and support for running PERL scripts on the
AS/400 system. Do not call the IBM support line for assistance. Comments and
questions should be directed to:
comp.lang.perl.misc or comp.sys.ibm.as400.misc newsgroups.
Note
For more information about PERL, see:
http://perl.com/perl/
2.14.6 Using VisualAge for Java to Create Applets and Applications
The VisualAge family of software application development tools allows
developers to construct applications visually by connecting prefabricated,
reusable software components from an expansive library of predefined classes
and parts from IBM and other vendors. IBM′s unique
visual-construction-from-parts technology will be extended to the Java
programming environment, enabling developers to visually build Java ″applets″.
″The new IBM Java tools will extend VisualAge′s powerful capabilities to the
World Wide Web, thus accelerating a developer′s path to Java.″
Java is an unparalleled cross-platform programming environment for the
Internet, allowing widespread distribution of ″applets″. An ″applet″ created in
Java can be downloaded from the Internet to anywhere in the enterprise,
immediately delivering critical information to the user. Java ″applets″ also
support user interaction, providing for delivery of ″live″ content (that is,
immediate computation of data) and manipulation of displays.
VisualAge for Java is the newest member of IBM′s acclaimed VisualAge family
of application development tools. Taking advantage of the hottest new
programming language in years, VisualAge for Java combines visual
construction from parts with the Java language to create a fully scalable,
end-to-end, object-oriented, rapid application development environment.
The promise of Java... and the power of VisualAge!
52
•
Take advantage of an object-oriented, rapid application development
environment including incremental compile capabilities.
•
Build secure, live Web applications using existing enterprise data and
perform transactions across multiple architectures and open protocols.
•
Implement live logic interpreter tests for your Java logic on the same
display.
•
Eliminate client configuration. Create ″Ready for Production″ applications or
applets.
•
Write it once and run it on multiple platforms including Windows 95, Windows
NT, OS/2, AIX, the AS/400 system, or MVS.
•
Enjoy true team-based environment with versioning for each developer.
•
Use standard parts definition including Java beans.
•
Get portable applications and reduced application development costs.
•
Use an incremental compiler for faster development.
Unleashing AS/400 Applications on the Internet
Reference
For more information about VisualAge Web directions, go to:
www.software.ibm.com/ad/visage/webwp.htm.
2.15 Application Security Considerations
The number of servers connecting to the Internet is growing at a phenomenal
rate going from a few thousand systems in 1994 to over 252 000 in June 1996. It
is estimated that there are over 50 million Web pages on the Internet. This
explosive growth of the Internet makes it increasingly an attractive way of doing
business. However, this vast quantity of information also makes it an attractive
environment for hackers.
Many systems are attacked. The Computer Security Institute released a survey
of corporate security specialists in May 1996 where 42% of them indicated they
had knowledge of unauthorized use of their systems in the preceding year. It is
to be assumed that the remaining 58% of the companies neither had or detected
any attack.
A break in, publicly known, can be damaging to your company′s reputation.
Would you want to do business with a bank that had reported a system break-in?
Certainly, large and well-known companies are a favorite target for intruders.
Being a small company should be of no consolation. Intruders know that small
businesses are less likely to be Internet savvy. Tools widely available on the
Internet enable new systems to be discovered quickly.
The threat is serious and no company should attach a system to the Internet
without understanding the risks involved.
Most of the Internet servers run on UNIX based systems. And it is widely
accepted that the AS/400 system has strong security features. Do these
capabilities make the AS/400 system immune from attacks from the Internet?
Unfortunately, networks in general and TCP/IP protocols and applications used
by the Internet in particular have inherent security issues that are problematic to
all kind of systems.
Technical insufficiency is one source that makes an Internet server vulnerable.
However, bear in mind that another source of threats is human errors such as
incorrect configuration or careless handling of passwords. And those risks are
independent from any hardware platform.
2.15.1 Related Publications
Securing Your AS/400 from Harm on the Internet , SG24-4929, discusses security
considerations when attaching an AS/400 system to the Internet.
Cool Title About the AS/400 and Internet , SG24-4815, helps you to understand
how to use and implement functions and features available with OS/400 V3R2
and V3R7 and the TCP/IP Connectivity Utilities/400, also known as Internet
Connection for AS/400.
Chapter 2. Internet Application Design Considerations
53
IBM SecureWay , AS/400 and the Internet , G325-6321, provides general security
information when you are thinking about connecting the AS/400 system to the
Internet.
The publications listed in this section are considered particularly suitable for a
more detailed discussion of the topics covered in this document.
Manuals
•
AS/400 TCP/IP Configuration and Reference, SC41-3420
•
Tips and Tools for Securing Your AS/400, SC41-3300
•
AS/400 Internet SecureWay, G325-6321
ITSO Publications
•
Cool Title About the AS/400 and Internet, SG24-4815
•
Building a Firewall with the IBM Internet Connection Secured Network
Gateway, SG24-2577
•
www.security, How to Build a Secure WWW Connection, SG24-4564
•
TCP/IP Tutorial and Technical Overview, GG24-3376
Paperbacks (can be ordered through IBM)
•
Implementing Internet Security, Frederic J. Cooper. Published by New Riders
1995, SR28-5744
•
Internet Firewalls and Network Security, Kranajit Sijan. Published by New
Riders 1995, SR28-5685
•
Network and Internet Security, Vijay Ahuja. Published by Academic Press
1996, SR23-7465
2.16 Internet URL References for More Information
Do you want to get more information?
For the latest detailed, product-specific information, visit the VisualAge for
Smalltalk Web site at URL:
http://www.software.ibm.com/software/ad/vastub.html
or the VisualAge for C++ site at:
http://www.software.ibm.com/ad/visualage_c++
or the IBM Internet Connection Family Web site at:
http://www.ibm.com/Internet
or the IBM AS/400 Internet Workshop Web site at:
http://www.as400.ibm.com/workshop/webbuild.htm
or the IBM Java Web site at:
http://ncc.hursley.ibm.com/javainfo
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Unleashing AS/400 Applications on the Internet
For more information on Lotus products, visit the Lotus site at:
http://www.lotus.com
Background on the Internet:
The Internet, Complete Reference, Second Edition;
by Harley Hahn
Spinning The Web; by Ford
Demographics & Statistics:
http://www.commerce.net/information/surveys/
TCP/IP Stuff:
Networking Personal Computers with TCP/IP; by Craig Hunt;
O′ Reilly & Associates, Inc.
A Beginner′ s Guide to HTML
http://www.ncsa.uiuc.edu/demoweb/html-primer.html
A few good books on HTML stuff:
Teach Yourself Web Publishing with HTML in 14 Days; by Laura Lemay
HTML for Dummies; by Tittel & James
HTML Publishing on the Internet for Windows; by Heslop & Budnick
HTML Quick Reference
http://kuhttp.cc.ukans.edu/lynx_help/HTML_quick.html
AS/400 Reference Manuals:
AS/400 Security Tips and Techniques, GC41-0615
AS/400 TCP/IP Configuration and Reference Manual, SC41-3420
Cool Title About the AS/400 and Internet, SG24-0372
AS/400 Security Reference, SC41-3302
Chapter 2. Internet Application Design Considerations
55
2.17 Road Map for Internet Application Design
Figure 16. Roadmap for Internet Application Design
The preceding chart can be used as a road map for choosing the right approach
for developing your Internet application.
56
Unleashing AS/400 Applications on the Internet
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
As an owner of an HTTP server on the Internet, you may sometimes see an
advantage in allowing the readers of your documents (HTML documents) to
return information back to your server, or let the readers retrieve certain kinds of
information from your server through the execution of special programs.
The mechanism for doing these or other similar functions is called the Common
Gateway Interface (CGI).
A programmer creates a gateway program and places it in the /CGI-BIN directory
of the server. A user of a Web page selects the gateway program URL as part of
using a Web page link, FORM, or ISINDEX query box. In response to the user
request, the gateway program executes and returns the results to the client.
3.1 HTTP CGI Programming Model
The HTTP Common Gateway Interface (CGI) programming model provides a
simple interface for running programs external to the HTTP server in a
platform-independent manner. This interface has been in use by the World Wide
Web since 1993. A good document that describes this interface can be found at
URL:
http://hoohoo.ncsa.uiuc.edu/cgi/interface.html
The purpose of CGI is to extend the capability of an HTTP server by providing
framework in which the HTTP server can interface with a program that is
specified on a URL. The format of the URL allows parameters to be passed to
the CGI program. On the server side, the interface describes how the program
is started by the HTTP server and how parameters for the program are passed
using a combination of standard-input and environment variables. It also
describes how output information (usually HTML elements) are passed back to
the HTTP server using standard output. Thus, in its simplest form, a CGI
program can be defined as a program that:
1. Can be called as an executable and run as a child process of the HTTP
server (this does not preclude the use of interpretive languages such as
REXX and PERL. In this case, their respective interpreters run as child
processes of the HTTP server).
Note: The CGI program on the AS/400 system runs within the same job as
the HTTP server.
2. Is able to read from the standard input.
3. Is able to access environment variables.
4. Is able to write to the standard output.
5. Is able to access ″command line″ arguments passed to main()
CGI programs can be as simple or as complex as the programmer wants to
make them, but clearly, the intent of the interface is to allow simple programs or
scripts to be developed quickly.
Given this definition of the CGI interface, the following characteristics are for CGI
programs:
 Copyright IBM Corp. 1997
57
58
•
They can be written in compiled programming languages or interpreted
scripts.
•
They can be simple five or six-line programs that serve a specialized
function or generalized business applications that do complex calculations
and database transactions (for example, order processing applications).
•
They are portable. As with any programming model, portability is a matter
of degree. To the extent that the program uses any operating system unique
interfaces or naming semantics, portability is reduced.
•
Since they run as a child process of the HTTP server, they can benefit from
the services provided by the server:
−
Communication over the HTTP protocol
−
Security
−
Firewall transparency. HTTP is usually allowed to pass through firewalls
(through socks or application gateways).
−
Resource mapping and name indirection provided by HTTP server
directives (program can be moved without affecting client URLs).
−
Error logging and audit logging provided by HTTP server
−
Course grained navigation provided by HTML documents
•
They provide process isolation. Since each CGI program runs in its own
child process, it has the security and integrity advantages that separate
processes offer.
•
They run in a connectionless environment. The HTTP server starts the CGI
program, it does its thing, and terminates. The output is sent to the browser
and the connection is broken. Subsequent requests for that same program
result in a new connection and a new instance. No state information is
maintained unless the CGI program had stored previous state information in
fields in the requesting HTML form or parameters in the requesting URL.
This characteristic comes about as a consequence of the Web′s hypertext
model that allows users to hop around from machine-to-machine across the
world at will. Forcing the browser to maintain persistent connections to all of
these machines is ridiculous.
•
Process start time often gates performance. The price to pay for process
isolation is to suffer the costs of process start time. In a connectionless
environment, this becomes an even bigger problem as the process must get
started for each request. The AS/400 HTTP model minimizes this penalty by
providing a pool of pre-started server jobs that minimize a majority of the
start-up costs. Add to that the ability to exploit named activation groups that
also eliminate program initialization costs, and the AS/400 CGI model starts
to look better than what is provided on other platforms.
•
They use short-running transactions. This is a consequence of the
connectionless model. The length of a transaction is limited to a single URL
request since that is the length of a process. This problem brings about the
requirement for the persistent CGI model described later.
•
The logic is almost entirely on the server. The CGI model is basically a
distributed presentation model where the logic is on the server and the client
is responsible for window presentation. The advantage of having the logic
on the server is apparent when the number of window interactions is far
smaller than the number of data accesses or the number of calculations
performed by the server.
Unleashing AS/400 Applications on the Internet
Although the CGI model is simple and universal, it has some definite
shortcomings. This is primarily due to its connectionless nature.
•
CGI program parameter data (passed as part of the URL) has portions
encoded with escape sequences. It is cumbersome for CGI programs to
decode these sequences after they have been converted from ASCII to
EBCDIC.
•
It is difficult for the CGI programs to determine and control what CCSIDs to
use when handling ASCII and EBCDIC data.
•
Multiple conversions from ASCII to EBCDIC of input and output data presents
some performance problems.
The basic idea of the CGI is illustrated in Figure 17.
Figure 17. The Basic Idea of How the CGI is Working
1. An HTML form is sent from the server to the Web client. Along with the form
is an action URL that points back to the CGI-bin program located someplace
on the network.
2. The browser is sending a request for a URL (Uniform Resource Locator)
resource from the server. This URL contains the name and path of the
CGI-bin application along with all of the form′s parameters.
3. The requested URL is a program - a Common Gateway Interface program.
The parameters are passed to the application program by one of two ways
depending on the form′s method of either post or get.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
59
4. The server is executing the CGI-program. While running, the CGI-program is
calling other programs or databases.
5. The CGI program passes the output from the other programs or databases
plus any additional information back to the server. This is done by writing to
the standard output of the application (stdout).
6. The server passes the information back to the browser. This information is
probably more HTML or a redirection indicator.
7. It is the browser′ s job to format the information it receives and display it.
URL
The URL specifies the address or location of a resource, such as CGI
programs, on the Internet. The URL looks similar to this:
protocol://host_name:port/pathname (?parameters)
To do all of this, a set of standards has been set on how to implement CGI
programs on your server so every possible Web browser that exists can access
your server and execute the CGI program.
3.2 Considerations Before You Start
The CGI program must be in the QSYS.LIB file system, which is the only file
system from which you can execute programs on the AS/400 system. The format
for a program call is:
Example:
/QSYS.LIB/library.LIB/program.PGM
The HTTP server does not execute a user-defined CGI program unless the HTTP
server administrator has explicitly enabled it by coding an Exec directive. The
HTTP server administrator can, for example, limit CGI requests to a specific
library in QSYS.LIB.
Example:
If you want the actual library specified where the program is stored:
Exec /QSYS.LIB/CGISAMPLE.LIB/*
That is specified in the URL:
http://hostname/QSYS.LIB/CGISAMPLE.LIB/SAMPLE.PGM
If you want the URL mapped into the library where the program is stored:
Exec /cgipgm/*
/QSYS.LIB/CGISAMPLE.LIB/*
That is specified in the URL:
http://hostname/cgipgm/SAMPLE.PGM
Note!
The minimum directives that you need to execute a CGI program are a Pass
and Exec directive.
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Unleashing AS/400 Applications on the Internet
The enable and disable directives cause the HTTP server to accept or reject
incoming request URLs based on the method coded in the URL. These methods
are described in the HTTP/1.0 specification. The AS/400 HTTP server supports
the GET, POST, and HEAD methods.
Example:
Enable GET
Disable POST
The AS/400 system runs CGI programs under the QTMHHTP1 user profile. The
QTMHHTP1 user profile must have authority to access all of the objects
accessed by the CGI programs (*PGM).
3.2.1 Required Configuration
You need:
•
TCP/IP configuration for the TCP/IP HTTP Server
•
Configuration of the AS/400 HTTP Server directives
HTTP Configuration
1. Use the WRKHTTPCFG command to change the HTTP server
configuration or CHGHTTPA command to change the HTTP server
attributes.
2. Refer to the following books to help you in configuring the HTTP server:
•
OS/400 TCP/IP Configuration and Reference V3 , SC41-3420
•
Cool Title About the AS/400 and Internet , SG24-4815
3.2.2 Overview of the Communication Between CGI Programs and the Server
The AS/400 HTTP server provides the means for a CGI program to read post
data from environment variables and standard input stream (stdin). The server
also provides the means for a CGI program to return data in the standard output
stream (stdout).
Necessary APIs (Application Program Interfaces) are available on the AS/400
system to support the environment variables, the standard input stream, the
standard output stream for RPG and COBOL programs, and also for C language
programs using SAA  C language library APIs.
The server and the CGI program communicates in four major ways, all
supported by the AS/400 system:
•
•
•
•
Environment variables
The command line
Standard input
Standard output
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
61
Figure 18. Ways of Communication for CGI Programs
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Unleashing AS/400 Applications on the Internet
3.3 CGI-BIN Programming
Usually the FORM tag is used to start the CGI program, based on variables
selected by the end user. Figure 19 shows an example on how to write an
HTML document with the FORM tag.
<html>
<head>
<title>Ordering an AS/400 Method=GET</title>
</head>
<body bgcolor=″#F8F8FF″>
<img align=middle src=″as400.gif″>
<b>
Ordering an IBM System AS/400 </b>
<p>
<b>Please fill in the following :</b>
<form method=″GET″ action=″ / BonusCGI/ORDAS400G.PGM″>
<INPUT type=″hidden″ name=″MBR″ value=″ORDAS400E ″ size=10>
Name :
<input type=text name=″NAME″ size=″30″ maxlength=″40″ clear=″all″>
<p>
Address :
<textarea name=″ADDRESS″ cols=30 rows=2 VALUE=″ ″>
</textarea>
<p>
<b>Which AS/400 would you like to order ?</b>
<br>
<input name=″TYPE″ value=″P1″ type=radio checked>Portable
<input name=″TYPE″ value=″P2″ type=radio>Server
<input name=″TYPE″ value=″P3″ type=radio>System
<p>
<b>Do you want the Support Line Service ?</b>
<br>
<input name=″SERV″ value=″T″ type=radio checked>Yes
<input name=″SERV″ value=″F″ type=radio>No
<p>
Please order :
<p>
<input type=submit VALUE=″Order″>
<input type=reset VALUE=″Clear Form″>
</form>
</P>
<A HREF=″ / web/DEMO2E.MBR″>Back</A> Demo-Menue
Figure 19. The HTML Source using the FORM Tag
When the Web browser displays the HTML document, it is similar to the following
figure.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
63
Figure 20. The HTML Document Using the FORM Tag Displayed by the Browser
A Form basically consist of three elements:
1. The Form method:
<FORM METHOD=″GET″ ACTION=″ / BonusCGI/ORDAS400G.PGM″>
or
<FORM METHOD=″POST″ ACTION=″ / BonusCGI/ORDAS400P.PGM″>
2. The Input tags:
text, textarea, checkbox, radiobutton, options...
3. Submit button
All three elements are used in Figure 19 on page 63. Note that the action
keyword contains the URL address to send the input data to when the Submit
button is pressed. In this case, a c t i o n = ″/ BonusCGI/ORDAS400x.PGM ″.
A match with an EXEC directive in our HTTP configuration enables the HTTP
server to execute a CGI program on behalf of the client.
In our case, action= ″ / BonusCGI/ORDAS400x.PGM″ is mapped with:
EXEC /BonusCGI/* /QSYS.LIB/ITSCOIC400.LIB/*
Note This!
Please note that only programs in the QSYS.LIB library may be the target for
the input data.
This is because only programs in the QSYS.LIB File system may be executed
on the AS/400 system.
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Unleashing AS/400 Applications on the Internet
The following figure shows the HTML output after the execution of the CGI-BIN
program.
Figure 21. The HTML Output Information Back on the Browser
Figure 22. Mapping of CGI URL to HTTP Configuration
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
65
There are two methods that can be used to access your forms. Depending on
which method you use, you receive the encoded results of the form in a different
way. The two methods are:
Method
Description
GET
If your form in the HTML document has METHOD=″GET″ in its FORM tag,
your CGI program receives the encoded form input in the
environment variable QUERY_STRING.
POST
If your form in the HTML document has METHOD=″POST″ in its FORM tag,
your CGI program receives the encoded form input on stdin. The
server does not send you an End of File (EOF) on the end of the data.
Instead, you must use the environment variable CONTENT_LENGTH to
determine how much data you should read from stdin.
Note This!
POST is often the preferred method of operating with CGI-BIN programming.
The reason why POST is preferred is that GET uses the environment variable
QUERY_STRING.
Some server platforms are limited in the length of environment variables.
A form with a lot of data can cause a loss of data.
In the POST method, there are no limits (all date is passed through STANDARD
INPUT, a way of transferring information in a ″stream″ without limits).
As you can see, the form method determines the way of passing the encoded
input data from the browser to the CGI program through the server. The server
and the CGI program communicates in four major ways, all supported by the
AS/400 system:
Environment variables
Used for the GET method.
The command line
Used in the case of an ISINDEX query.
Standard input
Used for the POST method.
Standard output
Used to produce output data.
The AS/400 HTTP server provides the means whereby called CGI programs can
access environment variables and standard input stream (stdin). The server
also provides the means for a CGI program to return data in the standard output
stream.
Request for programs in an HTML document can be made using either the GET
or the POST method. See Figure 23 on page 69 and Figure 24 on page 71.
Note This!
The AS/400 system runs CGI programs under the QTMHHTP1 user profile. The
QTMHHTP1 user profile must have authority to access all the objects
accessed by the CGI programs.
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Unleashing AS/400 Applications on the Internet
3.3.1 HTML Form Tags
The following table contains a quick summary of tags and attributes you can use
in your HTML documents inside FORM tag.
Table 2 (Page 1 of 2). HTML Form Tags
Tag
Use
<FORM>...</FORM>
A form. You can have multiple forms within a
document but forms cannot be nested.
METHOD
An attribute of the <FORM> tag indicating the
method with which the form input is given to the
script that processes the form input. Possible values
are GET and POST
ACTION
An attribute of the <FORM> tag indicating the
script to process the form input. Contains a relative
path or URL to the CGI program
<INPUT>
A form element
TYPE
An attribute of the <INPUT> tag indicating the type
of form element. Possible values are SUBMIT,
RESET, TEXT, RADIO, CHECKBOX, PASSWORD, and
HIDDEN. SUBMIT creates a button to submit the
form to the script that processes the input. RESET
creates a button that resets the default values of the
form, if any. TEXT creates a single-line text field.
RADIO creates a radio button. CHECKBOX creates a
check box. PASSWORD creates a single-line text
field, but the text is shown in encrypted form.
HIDDEN creates a form element that is not shown
but has a name and a value that can be passed onto
the script that processes the form input.
NAME
An attribute of the <INPUT>, <SELECT>, and
< T E X T A R E A > t a g s . Indicates the name of the
variable that holds the eventual value of this
element as submitted to the script.
VALUE
An attribute of the <INPUT> tag indicating the
default value for the form element, if any, or the
value submitted with the NAME of the script. For
SUBMIT and RESET buttons, VALUE indicates the
label of the button.
SIZE
An attribute of the <INPUT> tag used only when
TYPE is TEXT. Indicates the size of the text field in
characters.
MAXLENGTH
An attribute of the <INPUT> tag used only when
TYPE is TEXT. Indicates the maximum number of
characters this text field accepts.
CHECKED
An attribute of the <INPUT> tag used only when
TYPE is CHECKBOX or RADIO. Indicates that this
element is selected by default.
<SELECT>
A menu or scrolling list of items. Individual items
are indicated by the <OPTION> tag.
NAME
An attribute of the <SELECT> tag. Indicates the
name of the variable that holds the eventual value of
this element as submitted to the script.
MULTIPLE
An attribute of the <SELECT> tag indicating that
multiple items in the list can be selected.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
67
Table 2 (Page 2 of 2). HTML Form Tags
68
Tag
Use
SIZE
An attribute of the <SELECT> tag that causes the
list of items to be displayed as a scrolling list with
the number of items indicated by SIZE visible.
<OPTION>
Individual items within a <SELECT> element.
SELECTED
An attribute of the <OPTION> tag indicating that
this item is selected by default.
<TEXTAREA>
A text-entry field with multiple lines.
NAME
An attribute of the <TEXTAREA> tag. Indicates the
name of the variable that holds the eventual value of
this element as submitted to the script.
ROWS
An attribute of the <TEXTAREA> tag indicating the
height of the text field in rows.
COLS
An attribute of the <TEXTAREA> tag indicating the
width of the text field in characters.
Unleashing AS/400 Applications on the Internet
3.4 GET Method
Figure 23. AS/400 CGI Using the GET Method
As you can see in Figure 23, the flow is the same as in the basic chart for CGI
Figure 17 on page 59. The HTML document displayed by the browser uses
<FORM METHOD=″GET″ .
When the GET method is used, the input parameters are passed to the called CGI
program in one of two ways:
1. In command line parameters (program call parameters):
Parameters are passed to the CGI program using command line arguments
(program call parameters) only when the data in the request URL beyond the
first question mark (?) contains no equal signs (=). This is called an
ISINDEX. In the URL for an ISINDEX request, the CGI parameters are
positional (being separated by plus (+) signs). The server parses the
parameters and puts each parameter, according to its position in the string,
into corresponding parameters of the CGI program call.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
69
An example of a URL is:
http://sysnm003.sysnmaa.ibm.com/CGILIB/INDEX.PGM?value1+value2+value3
2. In the environment variable QUERY_STRING:
If the parameter string of the URL beyond the first question mark (?)
contains an equal sign (=), the entire parameter string is put into the
QUERY_STRING environment variable. This is the most normal case.
An example for the URL is:
http://sysnm003.sysnmaa.ibm.com/CGILIB/FORM.PGM?kwd1=value1&kwd2=value2&kwd3=value3
Note
The assumption is made that CGILIB has been mapped to a library in QSYS.LIB
containing CGI programs with the MAP and Exec directives for the AS/400
HTTP server.
The mapping directives allow the Web Administrator on the AS/400 system to
define a virtual hierarchy of Web resources that is presented by the AS/400
HTTP server. This virtual hierarchy is independent of the physical file system
(or systems) on which the resources are actually stored. This is useful since:
1. It allows resources to be physically relocated without changing the
apparent hierarchy and its implied associations.
2. The details of underlying physical file systems can be hidden from client
applications that are accessing the AS/400 HTTP server.
The second reason is especially important for the AS/400 HTTP server
because of the differences between some of the AS/400 file systems and the
tree structured hierarchical UNIX file systems upon which the HTTP protocol
and the URL scheme are based.
The mapping directives, MAP and Exec, are used to specify a set of rules that
define a process for translating and processing the path (and file) information
contained in a URL that is received in a client request URL.
Each of the mapping directives may be specified multiple times and in any
combination, and may be placed anywhere in the AS/400 HTTP server
configuration. When the AS/400 HTTP server configuration is read during
initialization, the mapping directives are stored in order of appearance in a
mapping rule table.
The incoming URL is compared against each of the specified mapping rules
in turn. If a directive applies, the specified translation is carried out.
Depending on the rule that was matched, rule processing is either suspended
or continues with the next rule using the newly translated URL.
The mapping and the exec definitions are created through the WRKHTTPCFG
command.
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3.5 POST Method
When the POST method is being used, the QUERY_STRING environment variable
contains a null string. The null string makes the CGI program look for its input
in the standard input stream. See Figure 24. The CGI program can determine
the method, GET or POST, from the REQUEST_METHOD environment variable.
Figure 24. AS/400 CGI using the POST Method
When the HTML document uses the <FORM METHOD=″POST″ , the form is submitted
with the standard input data stream, stdin. The CGI program inspects the
request method to determine if post data is available by reading the
REQUEST_METHOD environment variable. The CGI program can obtain other
environment variables set by the HTTP server regardless of the request method.
To support environment variables, the AS/400 HTTP server creates an
environment variable user index that contains the name and value for each
environment variable set by the server. The index is named QTMHENVI in the
QTEMP library.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
71
The reason why it is created in the QTEMP library is that it has to be unique for
each child job that defines it. So each child job creates the index that is
accessible to the CGI programs that the server child job calls.
Each time a CGI program is called, a new index is created and new environment
variables are set (preventing one CGI program from using the environment
variables intended for another CGI program). Creation of the index is not
dependent on the use of either method, GET or POST. The index is always
created.
The QTMHENVI index contains the following environmental variables:
Table 3. CGI Environment Variables in the QTMHENVI Index File
Environment Variable
Contain
QUERY_STRING
Information that follows the first question mark (?) in the
URL referencing the CGI program.
SERVER_SOFTWARE
The name and version of the information server
software answering the request (and running the
gateway).
SERVER_NAME
Host name, DNS alias, or IP address of the server.
GATEWAY_INTERFACE
The version of the CGI specification to which the server
complies.
SERVER_PROTOCOL
The name and revision of the information protocol this
request came in with.
SERVER_PORT
The port number to which the request was sent.
REQUEST_METHOD
The method with which the request was made. For
HTTP, this is ″GET″ or ″POST″.
PATH_INFO
The extra path information following the path
information required to identify the CGI program name.
PATH_TRANSLATED
The server provides a translated version of PATH_INFO,
which takes the path and does any virtual-to-physical
mapping to it.
SCRIPT_NAME
A virtual path to the program being executed.
REMOTE_HOST
The host name making the request.
REMOTE_ADDR
The IP address of the host name making the request.
REMOTE_USER
This is the user name making the request.
CONTENT_TYPE
For queries that have attached information, such as
HTTP POST, this is the content type of the data.
CONTENT_LENGTH
The length of data in the attached HTTP POST from the
client.
IBM_CCSID_VALUE
The CCSID under which the current server job is
running.
HTTP_ACCEPT
MIME content types the browser accepts.
HTTP_USER_AGENT
String identifying the Web client. Includes name and
version of the browser request made through a proxy
and other information.
HTTP_REFERER
Name of HTML document
When the CGI program has finished executing, it is expected to return an HTML
document or a redirection to an HTML document.
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The CGI program passes output from other programs or databases plus any
additional information back to the server. To do that, the CGI program uses the
standard output data stream, stdout.
3.6 AS/400 Programming Languages Supported
CGI programs are often called CGI scripts, but you can develop your own CGI
programs in many languages (not only in scripting languages). To select your
programming language, choose the one to use according to:
•
•
The task your application has to perform
Your programming skills
There is support for CGI programs written in:
•
•
•
•
C language
ILE RPG
ILE COBOL
REXX (See Section 3.10, “Programming CGI with REXX Language” on
page 93 for considerations and restrictions.)
Necessary APIs are available to support the environment variables, the standard
input stream, and the standard output stream.
The C language supports the environment variables through the getenv() API.
The standard input stream and the standard output stream are supported
through many APIs. Examples are fgets() and fwrite().
For the C programs, the APIs are found in the QTMHCGI *SVCPGM. A C language
header file member named QTMHCGI is provided in H file in library QSYSINC.
The APIs to support ILE RPG and ILE COBOL are provided in source files. The
source files are:
•
•
QCBLLESRC for ILE COBOL
QRPGLESRC for ILE RPG
Four APIs are provided:
Table 4. The APIs Provided for ILE RPG, ILE COBOL, and C Programs
Type of API
ILE RPG
ILE COBOL
C Language
Get Environment
Variable
QtmhGetEnv
QtmhGetEnv
getenv()
Read from Stdin
QtmhRdStin
QtmhRdStin
Many, for
example fgets()
Write to Stdout
QtmhWrStout
QtmhWrStout
Many, for
example fwrite()
Parse CGI input
QtmhCvtDb
QtmhCvtDb
# p r a g m a mapinc
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
73
Note This for RPG and COBOL!
For the CRTPGM, you must always specify the BNDSRVPGM QTCP/QTMHCGI to
ensure the module import for QtmhGetEnv, QtmhRdStin, QtmhWrStout, and
QtmhCvtDb are satisfied. If you forget to include the SRVPGM, you receive a
message similar to the following example:
Definition not found for symbol ′ QtmhRdStin′ .
Case Sensitive Alert!
The service program APIs of QtmhGetEnv, QtmhRdStin, QtmhWrStout, and
QtmhCvtDb are case sensitive. If you misspell one of them or if the case is
wrong for just one of the letters, you receive the following message after your
CRTPGM (the binding step) fails:
Message ID . . . . . . :
Message type . . . . . :
Date sent . . . . . . :
Message . . . . :
Cause . . . . . :
binding directory
Recovery . . . :
representative.
CPD5D1D
Diagnostic
10/30/96
Severity . . . . . . . :
20
Time sent . . . . . . :
14:33
*SRVPGM object QZDMMDTA in library QSOC not found.
*SRVPGM object QZDMMDTA in library QSOC was specified
QUSAPIBD in library *LIBL, but was not found for bind
Contact your application provider or service
This message is seemingly not related at all to the source of the problem.
The APIs are provided to simplify parsing form data from either stdin or from the
environment variable QUERY_STRING. The CGI program is expected to provide the
name of the DDS file specification that identifies the anticipated form variables
and their attributes.
The server times the operation CGI programs and terminates child server jobs
exceeding the time limit. There are three timeout keywords for input timeout,
output timeout, and script timeout.
Also, the server protects itself from CGI program exceptions by providing
exception handling that reduces any escape messages resulting from CGI
program failures to diagnostic messages.
3.7 Decoding the Parameters from the Remote Web Client
You now know that depending on the HTML form′s method, which can be either
POST or GET, the input string to your application is made available to your CGI
application running on the AS/400 system in either standard in or the
QUERY_STRING environment variable. If your application is in ILE C/400, you
have native I/O statements to code to retrieve the parameter string. If your
application is in ILE COBOL/400 or ILE RPG/400, IBM provides a service program
to do the job of reading the parameter string and placing it in a local program
variable.
What we have not covered is how this parameter string looks and what exactly
you must do to parse it into something that you can use in your application.
How to parse the string is dependant upon if you are writing your CGI application
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Unleashing AS/400 Applications on the Internet
in C/400 (see Section 3.8.2, “CGI Parameter Parsing with ILE C/400” on page 77),
or in either RPG/400 or COBOL/400 (see Section 3.9.2, “CGI Parameter Parsing
with ILE COBOL/400 or RPG/400” on page 86).
But first, let′s spend a little bit of time to understand the basic syntax of the
parameter string that we receive from a Web client.
3.7.1 CGI Parameter String Syntax
When you write the HTML form, each of your input items has a NAME tag
associated with it. As an example, take a look at the FORM tag (see Figure 25).
The first input field is a hidden field, which simply means that the end user does
not see this field nor is the user given the opportunity to modify the value
associated with it. The second named field is ″querydata″, which is presented to
the end user with the possibility to update. The input that is entered by the end
user for each input field is called the value.
<FORM
METHOD=″GET″ ACTION
=″ / BonusCGI/CGIENVGET.PGM″>
<INPUT type=″hidden″ name=″MBR″ value=″CGIENVGETE″ size=10>
<INPUT TYPE=text NAME=″querydata″ MAXLENGTH=″20″ VALUE=″ ″>
<BR>
<BR>
<INPUT TYPE=″SUBMIT″ VALUE=″Send Request″>
<INPUT TYPE=″RESET″ VALUE=″Clear Your Input″>
</FORM>
Figure 25. Two Named Input Fields Defined in the HTML Form
It is this stream of name=value pairs that flow back to your CGI application
running on the AS/400 system when the user selects the Submit button with the
mouse. These are the name=value pairs that you are reading either from
standard in or the QUERY_STRING environment variable.
One more thing must be mentioned. A well-behaved Web client can modify the
format of the parameter string. Each name=value pair is separated by the
ampersand (&) character. Also, each name=value pair is URL encoded, which
means spaces are changed into pluses (+) and some characters are encoded
into hexadecimal.
Again, using the same form shown in Figure 25, let′s assume that the end user
enters a value for querydata of:
AaBbCc, First three
The content of QUERY_STRING, as echoed back to the client by CGI program
CGIENVGET, is shown as:
MBR=CGIENVGETE&querydata=AaBbCc%2C+First+three
Let′s parse this string ourselves:
MBR=CGIENVGETE&querydata=AaBbCc%2C+First+three
|
|
| |
|
|
|
| Note : Spaces become plus (+) signs
|
|
Special characters, like the comma (,)
|
|
are represented as three ASCII character
|
|
escape sequences representing a hexadecimal
|
|
entry into an ASCII code page.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
75
|
Second name=value pair. The querydata name is case
|
sensitive. The value follows the equal (=) sign.
|
First name=value pair. The name is MBR and is case sensitive. The
value follows the equal (=) sign.
For more information about the format of the name=value pairs, we suggest that
you look on the Web. A good place to start is
http://hoohoo.ncsa.uiuc.edu/cgi/
To learn how to parse the name=value pairs coming from the Web client, keep
reading.
3.8 Programming CGI-BIN with ILE C/400
The C language supports the environment variables through the getenv() API.
The standard input stream and the standard output stream are supported
through many APIs. Examples are fgets() and fwrite().
For the C programs, the APIs are found in the QTMHCGI *SVCPGM. A C language
header file member named QTMHCGI is provided in H file in library QSYSINC.
To get the necessary prototypes, include the header file as follows:
#include <qtmhcgi.h>
Important Compiling Information!
Make sure QSYSINC is on your system before compiling programs that use
these header files because the QSYSINC library is optionally installable.
V3R2 Only
If you use the getenv() function, you must include the following header file:
#include <qp0z1170.h>
The version of getenv() that is in the stdlib.h header file does not work.
76
Unleashing AS/400 Applications on the Internet
3.8.1 Structure of C Program with POST Method
Figure 26. CGI Programming with C Language using POST Method
1. The HTML form is sent to the client. This form includes all of the named
fields that the user can click, select, pull down, or type in the answers. The
form tag also contains the method (in this case, POST) and the action (which
is the URL to which all the input parameters are sent). In the case of the
AS/400 system, this URL is your CGI application that runs in QSYS.LIB.
2. The user selects the Submit button. The HTTP server routes the data to the
CGI program, which places the named variables and values in Stdin. It calls
your CGI application, which can:
•
•
Read data from stdin using SAA C language library APIs such as fgets()
or fread().
Processing (anything that you want to do including access to DB2  /400
data).
•
Your CGI application must generate the HTML output that is going back
to the client.
•
Write data to stdout using SAA C language library APIs such as fwrite()
or printf().
3. When your application ends, whatever you wrote to stdout is sent back to the
Web client.
3.8.2 CGI Parameter Parsing with ILE C/400
If you are using ILE C/400 as your CGI application on the AS/400 system, you
have one advantage. And that advantage is that many other platforms, namely
UNIX based, also use C as a tool for writing CGI. And, if you have not figured it
out yet, you soon realize that the CGI interface was born and develop on UNIX
styled systems first. So, for the job of parsing the name=value pairs that come
from the Web client, we can go to the Web to pull down public domain C code
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
77
examples. This is what we did. For this example, please see Section 3.12.3,
“Source Code C Program PARSECGIP” on page 108.
We did need to modify the CGI parsing algorithm to work on the AS/400 system.
The problem with porting these routines came when the three-character escape
sequences (such as %2C that represents the comma (,) character) where being
translated into a single character. The code that we found on the Web assumed
that the native character set on the system it was running was ASCII. The
AS/400 system is EBCDIC, so we needed to modify the routine once we
understood the problem.
This, as we see in Section 3.9.2, “CGI Parameter Parsing with ILE COBOL/400 or
RPG/400” on page 86, is a problem in more than just this one place.
3.8.3 ILE C Sample Programs using POST and GET Methods
The following ILE C programs are examples of CGI programming using the POST
method and the GET method.
3.8.3.1 ILE C Program that Reads from Stdin (POST Method)
In this example, we use a function to read from the standard input stream
(stdin) and put the var=value pairs into the entries structure.
/****************************************************
/*
SAMPLE USING POST METHOD
*
/* Define struct for name = value pairs
*
/***************************************************/
typedef struct {
char *name;
char *val;
} entry;
entry entries[10000];
/****************************************************
/* Read CONTENT_LENGTH environment variable so know *
/* the length of data from the client
*
/***************************************************/
cl = atoi(getenv(″CONTENT_LENGTH″ ) ) ;
for(x=0;cl && (!feof(stdin));x++) {
m=x;
/***********************************************
/* Keep in entries struct name and value pairs *
/**********************************************/
entries[x].val = fmakeword(stdin,′&′,&cl); 1
plustospace(entries[x].val);
2
unescape_url(entries[x].val); 3
entries[x].name=makeword(entries[x].val,′ = ′ ) ; 4
}
1 Fmakeword function
This function reads a var=value pairs from stdin.
78
Unleashing AS/400 Applications on the Internet
char
*fmakeword(FILE *f, char stop, int *cl) {
int wsize;
char *word;
int ll;
wsize = 102400;
ll=0;
word = (char *) malloc(sizeof(char) * (wsize + 1));
while(1) {
word[ll] = (char)fgetc(f);
if(ll==wsize) {
word[ll+1] = ′ \0′ ;
wsize+=102400;
word = (char *)realloc(word,sizeof(char)*(wsize+1));
}
--(*cl);
if((word[ll] == stop) || (feof(f)) || (!(*cl))) {
if(word[ll] != stop) ll++;
word[ll] = ′ \0′ ;
return word;
}
++ll;
}
}
2 Plustospace function
This function changes the plus characters to space characters.
void
plustospace(char *str) {
register int x;
for(x=0;str[x];x++) if(str[x] == ′ + ′ ) str[x] = ′ ′ ) ;
}
3 Unescape_url function
When you write a special character in the browser, the HTTP server decodes it
in the %xx form. The unescape_url() function looks for the special characters and
if it finds them, calls the x2c() function to decode them.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
79
void
unescape_url(char *url) {
register int x,y;
for(x=0,y=0;url[y];++x,++y) {
if((url[x] = url[y]) == ′%′) {
url[x] = x2c(&url[y+1]);
y+=2;
}
}
url[x] = ′ \0′ ;
}
char x2c(char *what) {
register char digit;
digit=(what[0] >= ′ A′ ? ( ( what[0] & 0xdf) - ′ A′)+10 : (what[0]-′ 0 ′ ) ) ;
digit*=16;
digit+=(what[1] >= ′ A′ ? ( ( what[1] & 0xdf) - ′ A′)+10 : (what[1]-′ 0 ′ ) ) ;
return(digit);
}
4 Makeword function
At the end, separate the name of the value.
char
*makeword(char *line, char stop) {
int x = 0,y;
char *word = (char *) malloc(sizeof(char) * (strlen(line) + 1));
for(x=0;((line[x]) && (line[x] != stop));x++)
word[x] = line[x];
word[x] = ′ \0′ ;
if(line[x]) ++x;
y=0;
while(line[y++] = line[x++]);
return word;
}
3.8.3.2 ILE C Program that Reads from QUERY_STRING (GET
Method)
In this example, the GET method reads from QUERY_STRING using a getword()
function.
80
Unleashing AS/400 Applications on the Internet
/****************************************************
/*
SAMPLE USING GET METHOD
*
/* Define struct for name = value pairs
*
/***************************************************/
typedef struct {
char name[128];
char val[128];
} entry;
entry entries[10000];
/****************************************************
/* Read QUERY_STRING environment variable
*
/***************************************************/
cl=getenv(″QUERY_STRING″ ) ;
if( cl!=NULL ){
for(x=0 ; cl[0]!=′ \0′ ; x++){
m=x;
getword(entries[x].val, cl, ′ & ′ ) ; 1
plustospace(entries[x].val); 2
unescape_url(entries[x].val); 3
getword(entries[x].name,entries[x].val,′ = ′ ) ;
}
}
1 Getword function
This function reads from a string and looks for a character (in our sample,
ampersand to equal characters). If the character is found, the function stops and
returns the string.
void
getword(char *word, char *line, char stop) {
int x = 0,y;
for(x=0;((line[x]) && (line[x] != stop));x++)
word[x] = line[x];
word[x] = ′ \0′ ;
if(line[x]) ++x;
y=0;
while(line[y++] = line[x++]);
}
2 Plustospace funtion
This function is the same as the POST method. The data format is the same for
POST and GET methods; only the way it is received is different.
3 Unescape_url funtion
This function is the same as the POST method.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
81
3.9 Programming CGI-BIN with ILE RPG/400 and ILE COBOL/400
APIs are provided to allow programs written in COBOL and RPG to read stdin,
write to stdout, and read the environment variables. These APIs are found in the
QTMHCGI service program in the QTCP library.
The APIs to support ILE RPG and ILE COBOL are provided in source files. The
source files are:
•
•
QCBLLESRC for ILE Cobol
QRPGLESRC for ILE RPG
3.9.1 Structure of RPG Program Using POST Method
Figure 27. CGI Programming with RPG Language using POST Method
1. It is the same structure as the C program. The HTML form is sent to the
client.
2. It is the same structure as the C program. The user selects the Submit
button.
82
•
Call QtmhRdStin, which places the entire input string read from stdin into
a receiver variable of type pointer to character.
•
Call QtmhCvtDb, which parses the string of named variables and values
and places all of the data into a database file formatted by DDS.
•
Processing (anything that you want to do including access to DB2/400
data).
Unleashing AS/400 Applications on the Internet
•
The processing of your CGI application must generate the HTML output
that is sent back to the client.
•
Call QtmhWrStout to write the HTML to standard out (stdout).
3. When your application ends, whatever you wrote to stdout is sent back to the
Web client.
Note This for RPG and COBOL!
For the CRTPGM, you must always specify the BNDSRVPGM QTCP/QTMHCGI to
ensure the module import for QtmhGetEnv, QtmhRdStin, QtmhWrStout, and
QtmhCvtDb are satisfied. If you forget to include the SRVPGM, you receive a
message similar to the following example:
Definition not found for symbol ′ QtmhRdStin′ .
All APIs use a data structure for error reporting. This data structure is in:
•
QSYSINC/QRPGLESRC(QUSEC) and QSYSINC/QRPGSRC(QUSEC) for RPG
programs
•
QSYSINC/QCBLLESRC(QUSEC) and QSYSINC/QLBLSRC(QUSEC) for COBOL
programs
DQUSEC
D*
D QUSBPRV
D*
D QUSBAVL
D*
D QUSEI
D*
D QUSERVED
D*
D*QUSED01
D*
D*
DS
Qus EC
1
4B 0
5
8B 0
Bytes Provided
Bytes Available
9
15
16
16
17
17
Exception Id
Reserved
Varying length
Figure 28. QUSEC Data Structure for Error Reporting
•
The QtmhGetEnv API allows you to get the value set by the server for a
particular HTTP environment variable.
Table 5. Get Environment Variable (QtmhGetEnv) API
Description
I/O
Type
Example
Receiver variable
Output
Char(*)
name=fred&address=center+street
Llength of receiver variable
Input
Binary(4) 1
1024 max.
Length of response
Output
Binary(4)
31
Request variable
Input
Char(*)
QUERY_STRING
Length of request variable
Input
Binary(4)
12
Error code
I/O
Char(*)
QUSEC data structure (see Figure 28)
Note:
Reference at number of bytes, not at number of characters.
The following display shows a piece of RPG code using the QtmhGetEnv API.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
83
* Copy QUSEC structure
/copy qsysinc/qrpglesrc,qusec
D*QUSED01
17
116
* Variables for QtmhGetEnv
Denvrcvr
S
32767
Denvrcvrln
S
10i 0 inz(%size(envrcvr))
Denvrspln
S
10i 0
Denvrqsnm
S
30
Denvrqsln
S
10i 0
*
C
eval
qusbprv = 16
* Get environment variable
C
checkr
envrqsnm
envrqsln
C
CALLB
′ QtmhGetEnv′
C
parm
envrcvr
C
parm
envrcvrln
C
parm
envrspln
C
parm
envrqsnm
C
parm
envrqsln
C
parm
QUSEC
•
The QtmhRdStin API allows CGI programs to read from standard in (stdin).
Table 6. Read from Stdin (QtmhRdStin) API
Description
I/O
Type
Example
Receiver variable
Output
Char(*)
name=fred&address=Center+street
Length of receiver variable
Input
Binary(4)
1024 max.
Length of response
Output
Binary(4)
31
Error code
I/O
Char(*)
QUSEC data structure (see Figure 28 on
page 83)
The following display shows a piece of RPG code using the QtmhRdStin API.
* Copy QUSEC structure
/copy qsysinc/qrpglesrc,qusec
D*QUSED01
17
116
* Variables for QtmhRdStin
DInDataLn
S
10I 0
DInActLn
S
10I 0
Dbuffer
S
9999
*
C
eval
qusbprv = 16
* Standard input subroutine
C
CALLB
′ QtmhRdStin′
C
parm
C
parm
C
parm
C
parm
buffer
INDataLn
INActLn
QUSEC
•
The QtmhWrStout API provides the ability for CGI programs to write to
standard out (stdout).
Table 7. Write from Stdout (QtmhWrStout) API
Description
I/O
Type
Example
Data variable
Input
Char(*)
Content-type: text/html
Length of data variable
Input
Binary(4)
25
Error code
I/O
Char(*)
QUSEC data structure (see Figure 28 on
page 83)
84
Unleashing AS/400 Applications on the Internet
The following display shows a piece of RPG code using the QtmhWrStout
API.
* Copy QUSEC structure error
/copy qsysinc/qrpglesrc,qusec
D*QUSED01
17
116
* Variables for QtmhWrStout
DOUTBuffLn
S
10i 0
DOUTbuff
S
9999
*
C
eval
qusbprv = 16
* Standard output subroutine
C
callb
′ QtmhWrStout′
C
parm
OUTBuff
C
parm
OUTBuffLn
C
parm
QUSEC
•
The QtmhCvtDb API provides an interface for CGI programs to parse CGI
input defined as a series of keywords and their values into a buffer that is
formatted according to a DDS file specification.
Table 8. Convert to DB (QtmhCvtDb) API
Description
I/O
Type
Example
Qualified database file name
Input
Char(20)
′FILESAMPL LIBLSAMPLE′
Input string
Input
Char(*)
name=fred&addrees=center+street
Length of input string
Input
Binary(4)
31
Response variable
Output
Char(*)
FILESAMPL
Length of response variable
Input
Binary(4)
length of FILESAMPL
Length of response
available
Output
Binary(4)
Size required to contain the entire response
Response code
output
binary(4)
0=All keywords translated
-1=The database file contains extra fields
-2=The CGI input contains extra fields
-3=Combination of -1 and -2
-4=Different data types
Error code
I/O
Char(*)
QUSEC data structure (see Figure 28 on
page 83)
The following display shows a piece of RPG code using the QtmhCvtDb API.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
85
* Copy QUSEC structure
/copy qsysinc/qrpglesrc,qusec
D*QUSED01
17
116
* Variables for QtmhCvtDb
DDbFileName
S
DInData
S
32767
options(*varsize)
DInActLn
S
10i 0
DDSBuffer
S
32767
options(*varsize)
DDBDSLn
S
10i 0
DDBActLn
S
10i 0
DDBRespCd
S
10i 0
*
C
eval
qusbprv = 16
* Format the input data into the externally described data structure
C
CALLB
′ QtmhCvtDb′
C
parm
DDbFileName
C
parm
DInData
C
parm
DInActLn
C
parm
DDSBuffer
C
parm
DDBDSLn
C
parm
DDBActLn
C
parm
DDBRespCd
C
parm
QUSEC
3.9.2 CGI Parameter Parsing with ILE COBOL/400 or RPG/400
IBM has provided a service program routine by the name QtmhCvtDb to
automatically parse the name=value string and place the results in an
externally defined physical file (externally defined by DDS, of course). This
makes the job of parsing this rather complex string easy for ILE COBOL/400 and
ILE RPG/400 programmers as it is trivial to define and read in the fields
associated with the DDS file in RPG (as an example). This is the good news.
The bad news is that the QtmhCvtDb as shipped with V3R2 of the TCP/IP
Connectivity Utilities/400 has a bug in it (at the time of the writing of this
redbook) that causes it to make a mistake in the translation of the special
escape sequences (such a %2C) into the EBCDIC equivalent. The root cause of
the mistake lies in the same problem described in Section 3.8.2, “CGI Parameter
Parsing with ILE C/400” on page 77.
Here are some circumventions to the problem that can be used until IBM fixes
QtmhCvtDb:
1. Use the C sample program as mentioned in Section 3.8.2, “CGI Parameter
Parsing with ILE C/400” on page 77 to parse the string of name=value pairs.
This code is useful if you need to make some modification to the code for
your environment. You may find, for example, the translation table that we
use to convert ASCII to EBCDIC may not work for your environment.
2. You can always write the parsing code yourself in any language you want.
3. PID (IBM′ s Partners In Development) has made available a code snippet
(small section of source code) that you can place right before the call to
QtmhCvtDb. This code snippet modifies the string before the call by
changing the hexadecimal characters of the escape sequence that point to a
position in an ASCII code page into the EBCDIC representative. This causes
QtmhCvtDb to properly convert the escape sequences into a single EBCDIC
character.
When IBM fixes the problem with QtmhCvtDb, you simply remove the code
snippet.
86
Unleashing AS/400 Applications on the Internet
3.9.3 ILE RPG Program Using the POST and GET Methods
The following RPG program example shows pieces of RPG code fully functional
that serves as a model for building new CGI programs. This example is from a
more complex RPG program that you can find in the following URL:
http://www.as400.ibm.com/workshop/webbuild.htm
The functions used in this example are in a prototypes file (included in the
program by the /copy command), and the program calls them by the callp
command.
The program is called by an HTML page, reads the standard input stream and
the SCRIPT_NAME environment variable, and finally writes the HTML output.
****************************************************************************
* THIS SAMPLE CODE IS PROVIDED BY IBM FOR ILLUSTRATIVE
* PURPOSES ONLY. IT HAS NOT BEEN FULLY TESTED. IT IS
* PROVIDED AS-IS WITHOUT ANY WARRANTIES OF ANY KIND,
* INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE.
****************************************************************************
* This sample use a two external functions:
****************************************************************************
* Prototype definitions for gethtml and wrtsection functions
/copy prototypes
* Data structure for error reporting
/copy qsysinc/qrpglesrc,qusec
* Constants
DBufSize
C
32767
DOutBufSize
S
5i 0 inz(30000)
DDtaStrSize
C
55
* Variables for gethtml. Is the name of the file containing output
* HTML code with sections & variables (see fig x).
Dfn
S
10
INZ(′ HTMLSRC′ )
Dlib
S
10
INZ(′ CGIDEV′ )
Dmbr
S
10
INZ(′ OUTRPG′ )
* Names, values and lengths arrays for writing standard output.
* Used in setvardata subroutine and wrtsection function.
Dsection
S
10
Dvarnm
S
10
dim(50)
Dvarval
S
500
dim(50)
Dvarln
S
5I 0 dim(50)
Dv1
S
5i 0
* Variables for getenvf subprocedure
Denvrcvr
s
32767
Denvrcvrln
s
10i 0 inz(%size(envrcvr))
Denvrspln
s
10i 0
Denvrqsnm
s
30
Denvrqsln
s
10i 0
* Variables for getinf subprocedure
DInData
S
32767A
DInDataLn
S
10I 0 INZ(BufSize)
DInActLn
S
10I 0
DInDataType
S
5
* Variables for cvtdbf subprocedure. DbFileName MUST be UPPERCASE!
DDBFileName
S
20A INZ(′ DATASTRYCTCGIDEV
′)
DDBDSLn
S
10I 0 INZ(DtaStrSize)
DDBActLn
S
10I 0 INZ
DDBRespCd
S
10i 0 INZ
DDATASTRUCT
E DS
* Read environment variables
Dprogram
S
20A
Figure 29 (Part 1 of 2). RPG Source Code
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
87
****************************************************************************
* Mainline
****************************************************************************
C
eval
qusbprv = 16
* Read output html page
C
callp
gethtml(fn:lib:mbr) 1
* Get input data from POST or GET method
C
callp
getinput(indata:indataln: inactln:indatatype)2
* Format the input data into the externally described data structure
C
callp
CvtDb(DBFileName:InData:InActLn:datastruct: 3
C
DBDSLn:DBActLn:DBRespCd:QUSEC)
* Use getenvp to get the environment variables
C
eval
envrqsnm=′ SCRIPT_NAME′
C
′ ′
checkr
envrqsnm
envrqsln
C
exsr
getenvf
4
C
eval
program=%subst(envrcvr:1:envrspln)
* Setup data for writing standard output.
C
exsr
setvardata 5
* Write sections of HTML.
C
eval
section=′ top′
C
callp
wrtsection(section:varnm:varval:varln)
6
C
eval
section=′ variab′
C
callp
wrtsection(section:varnm:varval:varln)
C
eval
section=′ *fini′
C
callp
wrtsection(section:varnm:varval:varln)
C
eval
*inlr = *on
****************************************************************************
* Setvardata - Sets values of variable names, contents, lengths
****************************************************************************
C
setvardata
begsr
C
eval
v1=1
C
eval
varnm(v1)=′ NAME′
C
eval
varval(v1)=name
C
′ ′
checkr
varval(v1)
varln(v1)
C
eval
v1 = v1 + 1
C
eval
varnm(v1)=′ PROGRAM′
C
eval
varval(v1)=program
C
′ ′
checkr
varval(v1)
varln(v1)
C
endsr
****************************************************************************
* GETENVF. Call the QtmhGetEnv API
****************************************************************************
C
getenvf
begsr
C
callb
′ QtmhGetEnv′
C
parm
envrcvr
C
parm
envrcvrln
C
parm
envrspln
C
parm
envrqsnm
C
parm
envrqsln
C
parm
QUSEC
C
endsr
*********************************************************************** *****
Figure 29 (Part 2 of 2). RPG Source Code
1 Gethtml procedure
This procedure reads records from the HTML file CGIDEV/HTMLSRC/OUTRPG
and puts them into a dynamic array.
* Variables for gethtml (Is the name of the file containing HTML page output)
Dfn
S
10
INZ(′ HTMLSRC′ )
Dlib
S
10
INZ(′ CGIDEV′ )
Dmbr
S
10
INZ(′ OUTRPG′ )
* Read output html page
C
callp
gethtml(fn:lib:mbr)
The HTML page output is a special page and looks similar to the following
display:
88
Unleashing AS/400 Applications on the Internet
/$top
Content-type: text/html
<HTML>
<HEAD><TITLE>Demo POST method</TITLE></HEAD>
<BODY>
<H1>Environment variables</H1>
<HR>
<P>Welcome <B>/%name%/</B>,
/$variab
<TABLE Border Width=45% center>
<CAPTION><B>Here are some environment variables</B></CAPTION>
<TR><TH ALIGN=″left″>Variable</TH><TH ALIGN=″left″>Content</TH></TR>
<TR><TD ALIGN=″left″>SERVER_NAME</TD><TD ALIGN=″LEFT″>/%program%/</TD>
</TR>
</TABLE>
<HR>
</BODY>
</HTML>
This page has two special words that show the program where it should write
the sections and where it should write the variables identified by:
•
•
/$section
%variable%
2 Getinput procedure
In our sample, we call the getinput procedure with these parameters:
* Variables for getinput subprocedure
DInData
S
32767A
DInDataLn
S
10I 0 INZ(BufSize)
DInActLn
S
10I 0
DInDataType
S
5
* Call to getinput subprocedure
C
callp
getinput(indata:indataln:inactln:indatatype)
This function gets the REQUEST_METHOD environment variable to determine the
method used and reads input data from stdin (POST method) or using a
QtnhRdStin API, or reads from QUERY_STRING environment variable (GET
method) using a QtnhGetEnv API. This program also changes the escape
sequences and special characters (+) using the cgiparse procedure and keeps
the data in the getinput variables.
For a GET method, the subprocedure calls the getenvf procedure to read the
QUERY_STRING environment variable.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
89
**********************************************************************
* THIS SAMPLE CODE IS PROVIDED BY IBM FOR ILLUSTRATIVE PURPOSES ONLY
* IT HAS NOT BEEN FULLY TESTED. IT IS PROVIDED AS-IS WITHOUT ANY
* WARRANTIES OF ANY KIND, INCLUDING BUT NOT LIMITED TO THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**********************************************************************
Hnomain
/copy prototypes
/copy qsysinc/qrpglesrc,qusec
*
Pgetinput
b
export
Dgetinput
pi
DInData
32767
options(*varsize)
DInDataln
10i 0
DInActLn
10I 0
DInDataType
5
* Work variables
DDummy
s
like(InActLn)
* Variables for getenvf subprocedure
Denvrcvr
s
32767
Denvrcvrln
s
10i 0 inz(%size(envrcvr))
Denvrspln
s
10i 0
Denvrqsnm
s
30
Denvrqsln
s
10i 0
C
eval
qusbprv = 16
* Get request_method and put into indatatype
C
eval
envrqsnm=′ REQUEST_METHOD′
C
′ ′
checkr
envrqsnm
envrqsln
C
clear
envrcvr
C
exec
getenvf
C
eval
indatatype = %subst(envrcvr:1:envrspln)
* If requst method is post, Get content_length, convert to numeric,
* and put into inactln
C
if
indatatype=′ POST′
C
eval
envrqsnm=′ CONTENT_LENGTH′
C
′ ′
checkr
envrqsnm
envrqsln
C
clear
envrcvr
C
exsr
getenvf
C
eval
inactln=c2n(envrcvr)
C
endif
* If CONTENT_LENGTH is 0 and method = POST, set indata to blanks
* and return
C
if
indatatype=′ POST′ and inactln = 0
C
eval
indata = *blanks
C
return
C
endif
* Handle GET
C
select
C
when
indatatype=′ GET′
C
eval
envrqsnm=′ QUERY_STRING′
C
′ ′
checkr
envrqsnm
envrqsln
C
clear
envrcvr
C
exsr
getenvf
C
eval
indata = %subst(envrcvr:1:envrspln)
C
eval
inactln = envrspln
* Handle POST
C
when
indatatype=′ POST′
C
CALLB
′ QtmhRdStin′
C
parm
INData
C
parm
INDataLn
C
parm
dummy
C
parm
QUSEC
C
endsl
* Handle escape sequences, + signs, etc.
C
callp
cgiparse(indata:inactln)
C
return
**********************************************************************
Figure 30. Getinput Subprocedure Sample
3 CvtDb procedure
The CvtDb function moves the values read (by getinput function) to the DB file
fields (remember to code the external DS because the QtmhCvtDb API returns
90
Unleashing AS/400 Applications on the Internet
the data in this structure). In this sample, the data structure looks similar to the
following display:
A
A*
A*
A*
A
R SAMPLEREC
This field is the same as a field in the HTML input page
<INPUT NAME=″NAME″ SIZE=″40″ MAXLENGTH=″40″>
NAME
15
The program calls the CvtDb procedure.
* Variables for cvtdbf subprocedure. DbFileName MUST be UPPERCASE!
* and 20 characters long
*
10 characters for the file name
*
10 characters for the library name
DDBFileName
S
20A
INZ(′ DATASTRUCTCGIDEV
′)
DDBDSLn
S
10I 0 INZ(DtaStrSize)
DDBActLn
S
10I 0 INZ
DDBRespCd
S
10i 0 INZ
DDATASTRUCT
E DS
* Format the input data into the externally described data structure
C
callp
CvtDb(DBFileName&colonInData:
InActLn&colondatastruct:
DBDSLn&colonDBActLn&colonDBRespCd&colonQUSEC)
The CvtDb procedure calls the QtmhCvtDb API.
CvtDb
DbFileName
InData
InActLn
DSBuffer
DBDSLn
DBActLn
DBRespCd
qusec
extproc(′ QtmhCvtDb′ )
pr
20
32767
10i
32767
10i
10i
10i
16
options(*varsize)
0
options(*varsize)
0
0
0
4 Getenvf subroutine
The subroutine returns in the envrcvr variable, the SCRIPT_NAME environment
variable.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
91
* Variables for getenvf subprocedure
Denvrcvr
s
32767
Denvrcvrln
s
10i 0 inz(%size(envrcvr))
Denvrspln
s
10i 0
Denvrqsnm
s
30
Denvrqsln
s
10i 0
* Read environment variables
Dprogram
S
20A
* Use getenvp to get the environment variables
C
eval
envrqsnm=′ SCRIPT_NAME′
C
′ ′
checkr
envrqsnm
envrqsln
C
exsr
getenvf
C
eval
program=%subst(envrcvr:1:envrspln)
********************************************************************
* GETENVF. Call the QtmhGetEnv API
********************************************************************
C
getenvf
begsr
C
callb
′ QtmhGetEnv′
C
parm
envrcvr
C
parm
envrcvrln
C
parm
envrspln
C
parm
envrqsnm
C
parm
envrqsln
C
parm
QUSEC
C
endsr
5 Setvardata procedure
This procedure puts the content of variable = value pairs into arrays that the
wrtsection procedure uses later.
* Names, values and lengths arrays for writing standard output.
* Used in setvardata subroutine and wrtsection function.
Dsection
S
10
Dvarnm
S
10
dim(50)
Dvarval
S
500
dim(50)
Dvarln
S
5I 0 dim(50)
Dv1
S
5i 0
* Setup data for writing standard output.
C
exsr
setvardata
********************************************************************
* Setvardata - Sets values of variable names, contents, lengths
********************************************************************
C
setvardata
begsr
C
eval
v1=1
C
eval
varnm(v1)=′ NAME′
C
eval
varval(v1)=name
C
′ ′
checkr
varval(v1)
varln(v1)
C
eval
v1 = v1 + 1
6 Wrtsection procedure
At the end, the wrtsection subroutine uses the variables that have been
prepared by the setvardata subroutine and writes sections of HTML.
Wrtsection scans the delimiters for the sections (for example, ″/$top″) and the
delimiters for the variables (for example, ″ / % p r o g r a m % / ″) in the arrays, creates
the gethtml subroutine, and replaces the ″ / % v a r i a b l e % / ″ for the data.
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Unleashing AS/400 Applications on the Internet
* Names, values and lengths arrays for writing standard output.
* Used in setvardata subroutine and wrtsection function.
Dsection
S
10
Dvarnm
S
10
dim(50)
Dvarval
S
500
dim(50)
Dvarln
S
5I 0 dim(50)
Dv1
S
5i 0
* Write sections of HTML.
C
eval
section=′ top′
C
callp
wrtsection(section:varnm:varval:varln)
C
eval
section=′ variab′
C
callp
wrtsection(section:varnm:varval:varln)
C
eval
section=′ *fini′
C
callp
wrtsection(section:varnm:varval:varln)
The *fini section is not included in the HTML page because it is used only for
the wrtsection procedure to ensure that all output HTML that has been buffered
gets output.
This procedure calls the QtmhWrStout API to write in the standard output.
For RPG Programmers
We recommended using a debug in all of your programs. In the address:
http://www.as400.ibm.com/workshop/webbuild.htm
there is a good sample using a debugger.
3.10 Programming CGI with REXX Language
REXX programs cannot be used directly because REXX and the AS/400 Internet
Connection HTTP server do not handle standard input and standard output
compatibly. The REXX pull and say commands should not be used in CGI
scripts. If they are used, unpredictable results can occur, including function
checks in the HTTP server.
Because REXX procedures are not program objects, they cannot be invoked as
CGI programs. A CL program is invoked with a parameter containing the name
of the REXX procedure to be run in your form tag:
<form method=″POST′ action=″ / CGILIB/CLREXX.PGM?SAMPLE″>
The CL program CLREXX.PGM uses the STRREXPRC command to call the REXX
procedure. In this case, the REXXPROC variable is changed by SAMPLE:
PGM
PARM(&REXXPROC)
DCL
VAR(&REXXPROC) TYPE(*CHAR) LEN(10)
/* This command runs a REXX Procedure */
STRREXPRC SRCMBR(&REXXPROC)
MONMSG
MSGID(CPF0000) /* Ignore any errors */
ENDPGM
To enable compatibility with the HTTP server, the REXX program can call to
ILE-RPG programs that use QtmhRdStin, QtmhWrStout, and QtmhGetEnv APIs for
standard input and standard output operations.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
93
3.10.1 Structure of REXX Program Using POST Method
Figure 31. CGI Programming with REXX Language using POST Method
1. This point is the same as C and RPG languages. The HTML form is sent to
the client.
2. It is the same structure as the C and RPG programs. The user selects the
Submit button.
•
Call the CL program with the name of the REXX program.
•
Call QtmhRdStin through an RPG program. The QtmhRdStin API places
the entire input string read from stdin into a receiver variable of type
pointer to character.
•
Processing (anything that you want to do). This processing must
generate the HTML output.
•
Call QtmhWrStout through an RPG program. This API writes the HTML
code to standard output.
3. When your application ends, whatever you wrote to stdout is sent back to the
Web client.
94
Unleashing AS/400 Applications on the Internet
3.10.1.1 REXX Program Sample using POST Method
The next sample shows pieces of REXX code. The complete sample is in the
Internet address:
http://www.as400.ibm.com/workshop/webbuild.htm
In this REXX program, we read from stdin by the getparse procedure, and write
to the stdout by the sayh procedure.
/*******************************************************
* Initialization of variables
*
*******************************************************/
call initialize
/*******************************************************
* Read and parse data from stdin
*
*******************************************************/
call getparse
1
if alldataln > 0
then
do
/***********************************************
* Load translate table for use by handleescape *
***********************************************/
call gettable
/****************************
* Handle escaped characters *
****************************/
call handleescape
/****************************
/* Creates stem variables *
****************************/
call donames
end
/*******************************************************
* HTML output
*
*******************************************************/
title=′ This is the title′
call sayh ′ Content-type: text/html′
2
call sayh ′<HTML>′
call sayh ′<HEAD>′
call sayh ′<TITLE>′ title′ < / TITLE>′
call sayh ′ < / HEAD>′
call sayh ′<BODY>′
call sayh ′ Sample REXX procedure′
call sayh ′ < / BODY>′
call sayh ′ < / HTML>′
call sayh ′ ( ( ( ( ( flush′
exit
Figure 32. REXX Source Code
Now we try explain the most important subroutines used in this sample:
1 Getparse subroutine
This subroutine reads from standard input (uses a call to STDIN RPG program
that uses the QtmhRdStdin API) until no more input and concatenates all of the
input into variables.
When finished, it converts any plus (+) characters to blanks and separates
variable/value pairs.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
95
getparse:
if g.1jobtype=′ 1 ′
then
do
say ′ Enter standard input data′
parse pull alldata
alldataln = length(alldata)
end
else
do
alldata=′ ′
alldataln=0
g.1content_length=getenv(′ CONTENT_LENGTH′ )
g.1recvd = 0
if g.1content_length = 1 then return
/* Read from standard input
****************************/
do while g.1content_length > 0
if g.1content_length > g.1maxparmlength
then
g.1toget = g.1maxparmlength
else
g.1toget = g.1content_length
/* Calls the RPG program
*************************/
′ CALL PGM(STDIN) PARM(&g.1parm &g.1toget &g.1recvd)′
alldataln = alldataln + g.1recvd
alldata = alldata || substr(g.1parm,1,g.1recvd)
g.1content_length = g.1content_length - g.1toget
end
end
/* If the stdin is empty
*************************/
if alldata = ′ ′ | alldata = ′ ′
then
do
alldata=′ ′
alldataln=0
return
end
/* Translate ′ + ′ to blank
**************************/
alldata = translate(alldata,′ ′ , ′ + ′ )
g.1work = alldata
/* copy input data to work */
data.0 = 0
/* Separate the variable/value pairs (ampersand character)
and separate the variable and value (equal character)
*************************************************************/
do i = 1 while g.1work <> ′ ′
parse var g.1work data.i ′&′ g.1work /* parse va/value pairs */
parse var data.i varname.i ′ = ′ value.i
/* parse var. and value */
data.0 = data.0 + 1
/* increment variable count */
end
return
2 Sayh subroutine
This subroutine writes the data to standard out by calling the subroutine stdout.
First, it checks the line length and if it is larger than the maximum number of
characters allowed in a line without a newline, the sayh subroutine cuts the line
and calls the stdout function to insert a newline character at the end of the line
and write the string.
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Unleashing AS/400 Applications on the Internet
If the option (((((FLUSH appears in the argument list, see the stdout subroutine
(called by sayh). This option is a sample; you can use any string for identify the
end of the HTML document.
sayh:
procedure expose g.
parse arg x
/* read string argument */
do until x = ′ ′
/* Checks the lenght of the line
*********************************/
if length(x) <= g.1maxnonl
then
do
call stdout x
x = ′′
end
else
/* If the data has more than the maximum number allowed
********************************************************/
do
i = lastpos(′ ′ , x,g.1maxnonl)
if i = 0
then i = g.1maxnonl /* couldn′ t find blank, break at maximum */
y = left(x,i)
call stdout y
/* write first i bytes */
x = delstr(x,1,i)
/* delete first i bytes */
x = strip(x)
/* strip leading and trailing blanks */
end
end
return
The sayh subroutine calls the stdout subroutine.
Stdout inserts a newline character at the end of the line to make the data
conform to the ″newline character rule″ and writes the line in standard output by
a call to the STDOUT RPG program that uses a QtmhWrStout API.
If the option (((((FLUSH appears in the argument list, it forces any pending output
to standard output before processing the data.
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
97
stdout:
procedure expose g.
parse arg data ′ ( ( ( ( ( ′ options
dataln = length(data)
if g.1jobtype=′ 1 ′ / * an interactive job */
then
do
say data
end
else
do
/* Flush buffer if option = ′ FLUSH′ .
* This case is similar to write a EOF file. The
* browser needs to know when finish the output.
************************************************/
if wordpos(′ FLUSH′ , translate(options)) > 0
then
do
/* Calls the QtmhWrSout API.
***************************/
′ CALL PGM(STDOUT) PARM(&g.1stdout &g.1stdoutl)′
g.1stdout=′ ′
g.1stdoutl=0
if dataln = 0
then
return
end
/* If no newline charapter, appends at the end of the line.
***********************************************************/
if right(data,1) <> g.1newline then
data = data || g.1newline
dataln = length(data)
if (dataln + g.1stdoutl) > g.1maxparmlength
then
do
/* Calls the QtmhWrSout API.
****************************/
′ CALL PGM(STDOUT) PARM(&g.1stdout &g.1stdoutl)′
g.1stdout = data
g.1stdoutl = dataln
end
else
do
g.1stdout = g.1stdout || data
g.1stdoutl = g.1stdoutl + dataln
end
end
return
This program takes parameters and calls the API to write them in standard
stdout.
98
Unleashing AS/400 Applications on the Internet
/copy qsysinc/qrpglesrc,qusec
* Variables for QtmhWrStout
DOutBuffLn
S
10i 0
* Variables for entry parameter list. Note: 9999 is maximum size of C
DOutbuff
S
9999
DOutBuffPk
S
15P 5
Dnewline
C
x′ 1 5 ′
* Mainline calculations
C
*entry
plist
C
parm
outbuff
C
OutBuffln
parm
outbuffPk
*
C
eval
qusbprv = 16
* Standard output subroutine
C
callb
′ QtmhWrStout′
C
parm
OUTBuff
C
parm
OUTBuffLn
C
parm
QUSEC
C
return
REXX
We recommend not using PULL and SAY procedures in REXX CGI programs.
You can make a function that calls RPG programs that use a QtmhRdStin and
QtmhWrStout.
For REXX Programmers
We recommend using a debug method in all of your programs. In the
address:
http://www.as400.ibm.com/workshop/webbuild.htm
there is a good sample using a debugger.
3.11 Examples for Environment Variables
On the following pages, there are some inquiry examples for environment
variables.
Environment Variables with GET
Figure 34 on page 100 shows the inquiry results with the Method=GET.
The environment variable QUERY_STRING contains the name/value pairs!
Environment Variables with POST
Figure 36 on page 101 shows the inquiry results with the Method=POST.
The environment variable QUERY_STRING is empty.
POST always reads from STDIN!
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
99
The following figure shows the form for program CGIENVGET: Environment
Variables with METHOD=GET.
Figure 33. The HTML Document using the FORM Tag with M e t h o d = G E T
The following figure shows the HTML output from program CGIENVGET.
Figure 34. Document Returned from the Program CGIENVGET
100
Unleashing AS/400 Applications on the Internet
The following figure shows the form for program CGIENVPOST: Environment
Variables with METHOD=POST.
Figure 35. The HTML Document using the FORM Tag with M e t h o d = P O S T
The following figure shows the HTML output from program CGIENVPOST.
Figure 36. Document Returned from the Program CGIENVPOST
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
101
3.12 ITSO Company Example
Figure 37. Welcome to the ITSO Company Example
Table 9. Overview - Programs HTMLFILE=INPUT
Program
Function
Files
HTML-Mbr
HTMLO-Mbr
Language
CGIENVGET
Environment
Variables GET
ENVFILE
ENVGETDS
HTMLO
FORMGETE
CGIENVGETE
ILE RPG
CGIENVPOST
Environment
Variables POST
ENVFILE
ENVPOSTDS
HTMLO
FORMPOSE
CGIENVPOSE
ILE RPG
CGIGET
Search Online
Catalog
INVFILE
QUERYDS
L04P040
ILE RPG
CGIPOST
Feedback Talk To Us
TALKTOUS
TALKDS
L04P060
ILE RPG
ORDAS400G
Ordering an AS/400
GET
ORDAS00F
ORDASDS
HTMLO
AS4FORMGE
ORDAS400E
ILE RPG
ORDAS400P
Ordering an AS/400
POST
ORDAS00F
ORDASDS
HTMLO
AS4FORMPE
ORDAS400E
ILE RPG
PARSECGIP
Ordering an AS/400
POST
102
Unleashing AS/400 Applications on the Internet
RESIFORM
ILE C
3.12.1 Source Code RPG Program ORDAS400G
ILE RPG Program Example for the Method=GET
The information from the URL (value/name pairs) is assigned to the environment
variable QUERY_STRING.
This gateway program picks out the name/value pairs of the variables from this
QUERY_STRING through the API for ILE RPG:
The following example shows the Get Environment Variable QtmhGetEnv
(subroutine GETENV).
.
**************************************************************************
* Simple ILE RPG program ORDAS400G to test CGI Method=GET
*
*
* 1. Compile this source member as module ORDAS400G ( PDM Option=15 )
*
* 2. Create program ORDAS400G from module ORDAS400G ( PDM Option=26 )
*
with PROMPT(PF4) and BNDSRVPGM(QTCP/QTMHCGI)
*
* Define your files here
**************************************************************************
* Order Database file
**************************************************************************
FORDAS00F O A E
DISK
**************************************************************************
* HTMLFILE Input file ( read FORM input )
**************************************************************************
FHTMLFILE IF E
DISK
**************************************************************************
* HTMLO Output file ( prepared HTML Output in SRC-PF HTMLO )
*
( MBR = hidden field in HTML Input Form )
**************************************************************************
FHTMLO
IF E
DISK
USROPN RENAME(HTMLO:HTMLOUT)
**************************************************************************
A
|
|
|
|
|
|
|
A
*Variables for the CGI interface APIs
*These are for the APIEnVar
DENBuff
S
2048A INZ
DENBuffLn
S
9B 0 INZ(2048)
DENActLn
S
9B 0 INZ
DENVarName
S
64A INZ
DENVarLn
S
9b 0 INZ
*These are for the APICvtDB Datastructure INPUT fields
**************************************************************************
DDBFileName
S
20A INZ(′ ORDASDS *LIBL
′)
**************************************************************************
DDBBuff
S
2048A INZ
DDBBuffLn
S
9B 0 INZ(2048)
DDBDSLn
S
9B 0 INZ
DDBActLn
S
9B 0 INZ
DDBRespCd
S
9B 0 INZ
*These are used for APIStdOut
DOutBuff
S
2048A INZ
DOutBuffLn
S
9B 0 INZ(2048)
**************************************************************************
*Externally described data structure. Used for Parsing
*Need a different one in each CGI-BIN you write
DORDASDS
E DS
Figure 38 (Part 1 of 5). ILE RPG Program ORDAS400G M e t h o d = G E T
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
103
**************************************************************************
* Data structure for error reporting. Copied from QSYSINC/QRPGLESRC(QUSEC
DQUSEC
DS
D*
Qus EC
D QUSBPRV
1
4B 0 INZ(16)
D*
Bytes Provided
D QUSBAVL
5
8B 0
D*
Bytes Available
D QUSEI
9
15
D*
Exception Id
D QUSERVED
16
16
D*
Reserved
D*QUSED01
17
116
D*
D*
Varying length
**************************************************************************
*Constants for names of CGI APIs
DAPIStdIn
C
′ QtmhRdStin′
DAPIStdOut
C
′ QtmhWrStout′
DAPICvtDB
C
′ QtmhCvtDb′
DAPIEnVar
C
′ QtmhGetEnv′
*Compile-time array for OVRDBF
DOVRDBF
S
80
DIM(2) PERRCD(1) CTDATA
DOVRARR
S
1
DIM(80)
D**************************************************************************
D* Define NewLine
DNewLine
C
x′ 1 5 ′
D**************************************************************************
D* Define break
DBreak
C
′<BR>′
Figure 38 (Part 2 of 5). ILE RPG Program ORDAS400G M e t h o d = G E T
104
Unleashing AS/400 Applications on the Internet
****************************************************************
B
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
B
* Get the Environment Variable called QUERY_STRING
* Set the ENVarName to QUERY_STRING
*You must count the length of the Var Name!
*Set the ENVarLn to this length (12 In This Case)
C
MOVEL
*BLANKS
ENBuff
C
MOVEL
′ QUERY_STRING′ ENVarName
*****************************************************************
C
Z-ADD
12
ENVarLn
*****************************************************************
C
EXSR
GETENV
* Upon return, your Query_String data is in ENBuff with the len
* of the data returned in ENActLn
* Move this data to the DBCvt parms
**************************************************************************
C
Z-ADD
103
DBDSLn
**************************************************************************
C
MOVEL
ENBuff
DBBuff
C
Z-ADD
ENActLn
DBBuffLn
**************************************************************************
* Circumvention for HIDDEN fields ( find out MEMBER-NAME for HTMLO )
**************************************************************************
C
MOVEL
ENBuff
M14
14
C
MOVE
M14
M10
10
C
′+′:′ ′
XLATE
M10
MBR
10
*******************************************************************
* END Circumvention
********************************************************************
* Parse using the CvtDB API
C
EXSR
PARSE
* The field names in your Ext DS now
* contain the Values passed in the POST data
* Move them to the DB file fields
**************************************************************************
* OVR HTMLOUT with MEMBER ORDAS400 and open file
C
MOVEA
OVRDBF(1)
OVRARR
C
MOVEA
MBR
OVRARR(24)
C
MOVEA
OVRARR
CMD
80
C
Z-ADD
80
L
15 5
C
CALL
′ QCMDEXC′
C
PARM
CMD
C
PARM
L
C
open
HTMLO
*********************************************************************
* Move FORM Input to Database fields
**************************************************************************
C
MOVEL
NAME
NAME_X
C
MOVEL
ADDRESS
ADDRESS_X
C
MOVEL
TYPE
TYPE_X
C
MOVEL
SERV
SERV_X
*********************************************************************
* Write Database record file ORDAS00F
**************************************************************************
C
WRITE
ORDASR
* If you had multiple values for the same field, you would
* have lost all but the first. You need another technique for
* this situation
Figure 38 (Part 3 of 5). ILE RPG Program ORDAS400G M e t h o d = G E T
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
105
**************************************************************************
* Create the HTML Output
* Write HTML Required control records
* ADD NewLine append after 80 to 120 characters to OutBuff
**************************************************************************
C
DO
9
I
5 0
C
READ
HTMLOUT
98
C
OutBuff
cat
SRCDTA:0
OutBuff
C
OutBuff
CAT
NewLine:0
OutBuff
* Prepare variable OUTPUT
C
I
ifeq
9
C
OutBuff
CAT
Break:0
OutBuff
C
OutBuff
CAT
Break:0
OutBuff
C
OutBuff
cat
NAME:0
OutBuff
C
OutBuff
CAT
Break:0
OutBuff
C
OutBuff
cat
ADDRESS:0
OutBuff
C
OutBuff
CAT
NewLine:0
OutBuff
C
TYPE
ifeq
′ P1′
C
OutBuff
CAT
Break:0
OutBuff
C
OutBuff
CAT
Break:0
OutBuff
C
10
CHAIN
HTMLOUT
98
C
OutBuff
CAT
SRCDTA:0
OutBuff
C
OutBuff
CAT
NewLine:0
OutBuff
C
endif
C
TYPE
ifeq
′ P2′
C
OutBuff
CAT
Break:0
OutBuff
C
OutBuff
CAT
Break:0
OutBuff
C
11
CHAIN
HTMLOUT
98
C
OutBuff
CAT
SRCDTA:0
OutBuff
C
OutBuff
CAT
NewLine:0
OutBuff
C
endif
C
TYPE
ifeq
′ P3′
C
OutBuff
CAT
Break:0
OutBuff
C
OutBuff
CAT
Break:0
OutBuff
C
12
CHAIN
HTMLOUT
98
C
OutBuff
CAT
SRCDTA:0
OutBuff
C
OutBuff
CAT
NewLine:0
OutBuff
C
endif
C
OutBuff
CAT
Break:0
OutBuff
C
OutBuff
CAT
Break:0
OutBuff
C
SERV
ifeq
′ T′
C
13
CHAIN
HTMLOUT
98
C
OutBuff
CAT
SRCDTA:0
OutBuff
C
OutBuff
CAT
NewLine:0
OutBuff
C
else
C
14
CHAIN
HTMLOUT
98
C
OutBuff
CAT
SRCDTA:0
OutBuff
C
OutBuff
CAT
NewLine:0
OutBuff
C
endif
C
endif
C
ENDDO
C
MOVE
*OFF
*IN98
C
15
setll
htmlout
C
*IN98
DOWEQ
*OFF
C
read
htmlout
98
C
*IN98
CABEQ
*ON
EndHTM
C
OutBuff
cat
SRCDTA:0
OutBuff
C
OutBuff
CAT
NewLine:0
OutBuff
C
EndHTM
TAG
* End variable OUTPUT
C
ENDDO
Figure 38 (Part 4 of 5). ILE RPG Program ORDAS400G M e t h o d = G E T
106
Unleashing AS/400 Applications on the Internet
*
C
C
C
C
*
C
c
C
*
C
C
C
C
C
C
C
*
*
C
|
|
|
|
|
|
|
|
|
|
C
Read HTMLFILE until EOF
MOVE
*OFF
*IN99
*IN99
DOWEQ
*OFF
READ
HTMLREC
99
ENDDO
Send OutBuff to standard output
OutBuff
CAT
NewLine:0
OutBuff
′ ′
CHECKR
OutBuff
OutBuffLn
EXSR
STDOUT
End program
CLOSE
HTMLO
MOVEA
OVRDBF(2)
OVRARR
MOVEA
OVRARR
CMD
80
CALL
′ QCMDEXC′
PARM
CMD
PARM
L
MOVE
*ON
*INLR
These are the APIs used in subroutines to keep the main processing
simple. They do not need to be SUBRs!
* Subroutine to Get Environment Variable
C
GETENV
BEGSR
C
CALLB
APIEnVar
C
parm
C
parm
C
parm
C
parm
C
parm
C
parm
C
ENDSR
ENBuff
ENBuffLn
ENActLn
ENVarName
ENVarLn
QUSEC
C* Parse subroutine
C
PARSE
BEGSR
C
CALLB
APICvtDB
C
parm
DBFileName
C
parm
DBBuff
C
parm
DBBuffLn
** Remember to code your External DS name. The API returns your data
** in this structure. The field names are in the structure
**************************************************************************
C
parm
ORDASDS
**************************************************************************
C
parm
DBDSLn
C
parm
DBActLn
C
parm
DBRespCd
C
parm
QUSEC
C
ENDSR
* This is the STD OUT SUBR
C
STDOUT
BEGSR
C
callb
APIStdOut
C
parm
OUTBuff
C
parm
OUTBuffLn
C
parm
QUSEC
C
ENDSR
**CTDATA OVRDBF
OVRDBF FILE(HTMLO) MBR(1234567890) LVLCHK(*NO) OVRSCOPE(*JOB)
DLTOVR FILE(HTMLO) LVL(*JOB)
Figure 38 (Part 5 of 5). ILE RPG Program ORDAS400G M e t h o d = G E T
3.12.2 Source Code RPG Program ORDAS400P
ILE RPG Program Example for the Method=POST
The logic of this program is identical with the program in Figure 38 on page 103.
Only three parts are replaced:
A by 1
B by 2
C by 3
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
107
This CGI program receives the name/value pairs from the form as encoded form
input from STDIN.
The environment variable CONTENT_LENGTH determines how much data must be
read from STDIN.
The following example shows the Read from STDIN QtmhRdStin (subroutine
STDIN).
1
**************************************************************************
*Variables for the CGI interface APIs
*These are used for APIStdIn
DInData
S
2048A INZ
DInDataLn
S
9B 0 INZ(2048)
DInActLn
S
9B 0
**************************************************************************
2
**************************************************************************
* Get the Input parameters from the POST from STDIN
C
MOVE
*BLANKS
OutBuff
C
EXSR
STDIN
* Upon return, your POST data is in INData and its length is in
* INActLn It is in the FLD=VAR format at this time
* Move this data to the DBCvt parms
* Set up the parameters before CALLB
* This includes the length of your Ext DS (103 is correct)
**************************************************************************
C
Z-ADD
103
DBDSLn
**************************************************************************
C
MOVEL
INData
DBBuff
C
Z-ADD
INActLn
DBBuffLn
**************************************************************************
3
**************************************************************************
* Subroutine to read STD IN
C
STDIN
BEGSR
C
CALLB
APIStdIn
C
parm
INData
C
parm
INDataLn
C
parm
INActLn
C
parm
QUSEC
C
ENDSR
**************************************************************************
Figure 39. ILE RPG Program ORDAS400P M e t h o d = P O S T
3.12.3 Source Code C Program PARSECGIP
ILE C Program Example for the Method=POST
This is the program for Ordering an AS/400 system in the C-Language.
C Programs #include qp0z1170.h
The qp0z1170.h must included to get the getenv() and putenv() functions,
which are not part of the stdio.h at this time.
The qp0z1170.h is a member in the file H in the library QSYSINC.
108
Unleashing AS/400 Applications on the Internet
/************************************************************************
/*
*
/* Simple ILE C program PARSECGIP to test CGI Method=POST
*
/*
*
/************************************************************************
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <qp0z1170.h>
#define MAX_ENTRIES 10000
typedef struct {
char *name;
char *val;
} entry;
char
char
char
void
void
*makeword(char *line, char stop);
*fmakeword(FILE *f, char stop, int *len);
x2c(char *what);
unescape_url(char *url);
plustospace(char *str);
main(int argc, char *argv[]) {
entry entries[MAX_ENTRIES];
register int x,m=0;
int cl;
printf(″Content-type: text/html\n\n″ ) ;
if(strcmp(getenv(″REQUEST_METHOD″ ) , ″ POST″)) {
printf(″This script should be referenced with a METHOD of POST.\n″ ) ;
exit(1);
}
if(strcmp(getenv(″CONTENT_TYPE″ ) , ″ application/x-www-form-urlencoded″)) {
printf(″This script can only be used to decode form results. \n″ ) ;
exit(1);
}
cl = atoi(getenv(″CONTENT_LENGTH″ ) ) ;
for(x=0;cl && (!feof(stdin));x++) {
m=x;
entries[x].val = fmakeword(stdin,′&′,&cl);
plustospace(entries[x].val);
unescape_url(entries[x].val);
entries[x].name = makeword(entries[x].val,′ = ′ ) ;
}
printf(″<html>\n″ ) ;
printf(″<body>\n″ ) ;
printf(″<H1>Query Results</H1>″ ) ;
printf(″You submitted the following name/value pairs:<p>″ ) ;
printf(″<ul>″ ) ;
for(x=0; x <= m; x++)
printf(″<li> <code>%s = %s</code>″ , entries[x].name,
entries[x].val);
printf(″</ul>″ ) ;
printf(″</body>\n″ ) ;
printf(″</html>\n″ ) ;
}
Figure 40. ILE C Program PARSECGIP M e t h o d = P O S T
Chapter 3. Common Gateway Interface (CGI-BIN) Implementation
109
110
Unleashing AS/400 Applications on the Internet
Chapter 4. Net.Data Implementation
With the explosion of intranets and the Internet, there is a growing demand for
access to dynamic Web pages.
Net.Data allows people with little programming knowledge to easily transform
static HTML Web pages into dynamic Web applications using ″Net.Data Macros″.
Macros created for Net.Data have the simplicity of HTML with the functionality of
CGI applications, making it easy to add live data to static Web pages. Live data
can include information stored in Net.Data compatible databases locally or on
other systems, REXX programs, C and C++ programs, RPG programs, COBOL
programs, Java applets, or any other source.
4.1 An Overview of Net.Data for AS/400 System
Figure 41. Net.Data Overview
Net.Data enables the application developer to build Web applications on the
AS/400 system using a simple macro language that includes HTML forms,
dynamic SQL, REXX, and high-level language programs. End users of Net.Data
Web macros see only the forms for their input and reports showing the results.
A user fills out the forms, points and clicks to submit the form, and Net.Data
processes the request as determined by the macro. The complete HTML page is
dynamically built by Net.Data and the result is returned to the browser.
 Copyright IBM Corp. 1997
111
Figure 42. Net.Data General Overview
The Macro language was developed to be a simple and flexible language,
enabling the application developer to use the full capabilities of HTML to create
forms and reports. The application developer creates HTML source, SQL
commands, and calls to other language environments and stores them in macro
files at the Web server. Variables are used to link the Macro language
commands and the HTML source within the macro file. The macro files are
processed by Net.Data and the results are passed to the HTTP server.
4.1.1 Beyond DB2WWW Connection
Net.Data is an upwardly-compatible follow-on version of the DB2 World Wide
Web Connection (DB2WWW) that was first shipped with OS/400 Version 3
Release 2 (V3R2), and builds on the strong database access and report creation
abilities of that version.
By providing significantly increased data access and manipulation capabilities,
Net.Data has become a comprehensive, general-purpose Web application
development environment for the creation of interactive, data-centric Web
applications.
4.1.2 Features and Functions
Net.Data was designed with the following objectives:
•
To not require extensive programming by the application developer other
than the use of HTML to create forms, SQL for queries and updates against
the database, REXX for string manipulation and more advanced functions,
and the Advanced Macro Language for ease-of-use functionality. For more
information about REXX, see:
http://rexx.hursley.ibm.com/
112
•
To be flexible for a variety of Web applications that can grow from simple to
complex.
•
To be portable to multiple server platforms.
Unleashing AS/400 Applications on the Internet
•
To be usable with existing Web HTML editors and database query tools.
Net.Data has the following features:
•
Net.Data applications can use native HTML, SQL, and REXX, thus exploiting
the expressive power of these languages without artificial limitations.
•
Net.Data is small and efficient, and has been ported to multiple platforms.
•
Visual tools may be used to partially generate Net.Data macro files. Third
party vendors′ visual HTML editors can be used to generate the HTML
sections, while various visual query tools such as IBM ′ s Visualizer Query
may be used to generate the SQL sections.
4.1.3 Generalized Data Sources
Net.Data, with its enhanced functionality, can use a variety of data sources to
build dynamic Web pages:
•
•
•
•
•
DB2, through SQL
REXX programs
C programs
COBOL, RPG programs
Built-in functions
4.1.4 Advanced Macro Language
Net.Data Web macros combine things you already know such as HTML, SQL, and
REXX with a simple macro language. Capabilities of the macro language
include:
•
Multiple, named HTML sections in one macro
•
Ability to include files
•
If-Then-Else
•
Function definitions
•
Large library of predefined functions
•
Access to environment variables
•
Ability to disable the default report
•
Table variables
•
Ability to specify multiple paths for macros, executable, and includes
•
Persistent database connections
•
An external interface for user-supplied language environments that can
provide new sources to data
Examples of the previous functions can be found in Section 4.2, “Writing Net.Data
Macro Files” on page 114. To find out more information about the Net.Data
macro language, see the online Net.Data Reference Guide at:
http://www.software.ibm.com/data/net.data/docs/
Chapter 4. Net.Data Implementation
113
4.1.5 Net.Data and Internet Security
The following section is a general description of Net.Data and security. To use
these functions with the AS/400 system, you need IBM′s V4R1 secure server
Net.Commerce or I/NET′s Commerce server.
Net.Data works with the DB2 database, the Web server, and the firewall products
to provide secure data access over the Internet. When used with one or more of
these other products, the types of security provided are as follows:
•
Authentication: Net.Data can take advantage of two types of authentication
(user login and password), one provided by the Web server and the other by
DB2. They are as follows:
−
Web servers can typically be configured to protect certain directories on
the server. When a URL accesses a file in that directory, login and
password pop-up windows appears on the end user′s Web browser to
request for authentication.
−
DB2 has a login/password authentication mechanism for database
access. This mechanism can be used to restrict access to tables and
columns by certain users.
•
Encryption: Net.Data, when used with a secure Web server that has support
for Secure Sockets Layer (SSL) or Secure Hypertext Transfer Protocol
(SHTTP), or both, benefits from the public key encryption scheme provided
by the secure Web server and secure Web client. The user login and
password used for authentication are encrypted for transmission, as well as
all user inputs to the forms and the query results that are sent back to the
user. A secure Web server/client combination is a must for protection of
sensitive data.
•
Firewall: Net.Data may be used with firewall products such as NetSP for
IBM, which protects both the Net.Data machine and the corporate network
from external Internet attacks.
For more information on protecting your assets, see the Internet security list of
frequently asked questions (FAQ) at this Web site:
http://www-genome.wi.mit.edu/WWW/faqs/www-security-faq.html
For the most secure access to DB2 data, Net.Data should be used in conjunction
with both a secure Web server and a firewall.
4.2 Writing Net.Data Macro Files
When Net.Data is used as a CGI application, it calls the executable DB2WWW
and one or more language environments.
Language environments are Net.Data′s interface to your data and applications.
Each language environment provides a specific interface. For example, Net.Data
provides language environments to access DB2 databases, REXX, C, C++,
RPG, and COBOL applications. Net.Data also lets you build your own language
environments.
The Web macro contains a series of macro language, HTML, and language
environment-specific statements. Language environment-specific statements
can be from languages such as SQL and REXX.
114
Unleashing AS/400 Applications on the Internet
When a URL is received by the Web server that refers to Net.Data, the Web
server passes essential information to it, including the name of the Web macro
and the HTML section to process. Net.Data reads and parses through the Web
macro and interprets the statements. When a Net.Data function call statement is
encountered, it loads the service program of the requested language
environment and passes language-specific information to the language
environment for processing. The language environment processes the
information and returns the results to Net.Data. After all parsing is done and the
language environment processing is completed, all that remains is HTML text
that any Web browser can interpret. You have complete control over the HTML
that is used. The HTML text is passed back to the Web server. The server
passes it to the Web browser where the user interacts with it. Further requests
from this or any other user results in the process being repeated over again.
Net.Data Macro files consist of multiple logical sections. The most common
sections are the Define section , Function section , HTML Input section , and the
HTML Output section . The following sample is a Net.Data Macro file.
Figure 43. Net.Data Macro Files
Chapter 4. Net.Data Implementation
115
Notice that the following macro consists of four major logical sections: the
Define section, the Function Definition section, the HTML Input section, and the
HTML Output section. You can have several HTML sections, but this simple
example only has two.
Also notice that the two HTML sections contain familiar HTML tags, which makes
writing Web macros easy. If you are familiar with HTML, building a macro
simply involves adding macro statements to be processed dynamically at the
server.
Although the macro file looks similar to an HTML document, the Web server
accesses it through Net.Data as a CGI program. Net.Data expects two
parameters: the name of the macro to process and the HTML section in that
macro to display.
To understand what happens when a macro is executed, let′s go through the
following example macro section-by-section and see what each statement
means.
%{ ********
Define Section
*********%}
%DEFINE {
page_title=″Web Macro Template″
%}
%DEFINE { DATABASE=″*LOCAL″ TABLE=″LIB.FILE″
Mytable=%TABLE(ALL) %}
%{ ******** Function Definition Section *********%}
%FUNCTION(DTW_REXX) rexx1 (IN input) returns(result)
{ %EXEC{/qsys.lib/netdatawww.lib/qrexsrc.file/ompsamp.mbr %}
%}
%FUNCTION(DTW_REXX) today () RETURNS(result)
{
result = date()
%}
%{ *******
HTML Section: Input
%HTML (INPUT) {
<html>
<head>
<title>$(page_title)</title>
</head>
<body>
<h1>Input Form</h1>
<hr>
Today is @today()
**********%}
<FORM METHOD=″post″ ACTION=″output″>
Type some data to pass to a REXX program:
<INPUT NAME=″input_data″ TYPE=″text″ SIZE=″30″>
<p>
<INPUT TYPE=″submit″ VALUE=″Enter″>
</FORM>
<hr>
<p>
[
<a href=″/″>Home page</a>
]
116
Unleashing AS/400 Applications on the Internet
</body>
</html>
%}
%{ ******
HTML Section: Output
%HTML (OUTPUT) {
<html>
<head>
<title>$(page_title)</title>
</head>
<body>
<h1>Output Page</h1>
<hr>
<p>@rexx1(input_data)
<p>
<hr>
<p>
[
<a href=″/″>Home page</a> |
<a href=″input″>Previous page</a>
]
</body>
</html>
**********%}
%}
4.2.1 Define Section
The Define section allows you to set up the variables that are used in the macro.
%{ ********
Define Section
*********%}
%DEFINE { page_title=″Web Macro Template″
%}
%DEFINE { DATABASE=″*LOCAL″ TABLE=″LIB.FILE″
Mytable=%TABLE(ALL) %}
Figure 44. Define Section of Web Macro
The first line is a comment. The format of a comment is %{ ...one or more
comment lines... %} . Comments usually appear before each macro section.
They cannot appear in a macro section. The next statement starts a DEFINE
section. You can define multiple variables in one define section. In this
example, only one variable, ″page_title″, is defined. Once defined, this variable
can be referenced anywhere in the macro using the syntax, $(page_title). Using
variables makes it easy to make global changes to your macro later. The second
DEFINE establishes what database to connect to (it can be local or remote). The
database must be defined in the ″Relational Database Directory using the
WRKRDBDIRE command. The last line of this section, ″%}″, identifies the end of
the DEFINE section.
Chapter 4. Net.Data Implementation
117
4.2.2 Function Definition Section
The function definition section allows you to define the language environments
you use and what parameters are passed to the language environment.
%{
********************** Function Definition Section ************************%}
%FUNCTION(DTW_REXX) rexx1 (IN input) returns(result)
↑This function accepts one parameter
and returns a result which is substituted
for the associated function call
{ %EXEC{/qsys.lib/netdatawww.lib/qrexsrc.file/ompsamp.mbr %}
↑ This function executes an
external REXX program called ″ompsamp.mbr″
%}
%FUNCTION(DTW_REXX) today () RETURNS(result) {
result = date()
←The single source statement for this function is
contained inline.
%}
Figure 45. Function Definition Section
This function definition section contains two function declarations. The first,
″rexx1″, is a REXX function declaration that, in turn, executes an external REXX
program called ″ompsamp.cmd″. One input variable, ″input″, is accepted by this
function and automatically passed to the external REXX command. The REXX
command also returns one variable called ″result″. The contents of the ″result″
variable in the REXX command replaces the invoking @rexx1() function call
contained in the OUTPUT section. The variables ″input″ and ″result″ are directly
accessible by the REXX program as you can see in the following source for
″ompsamp.cmd″:
/* REXX */
result = ′ The REXX program received ″ ′ input′ ″ from the macro.′
The code in this function echoes the data that was passed to it. You can format
the resulting text any way you want by enclosing the requesting @rexx1()
function call in normal HTML style tags (such as <b> or <em>). Rather than
using the ″result″ variable, the REXX program can have written HTML statements
to standard out using REXX SAY statements. Although this is acceptable, it
minimizes the degree of separation between program logic and screen
presentation.
The second function declaration, ″today″, also refers to a REXX program.
However, the entire REXX program (one entire line, in this case) is contained in
the function declaration itself. An external program is not needed. Inline
programs are allowed for REXX functions because it is an interpreted language
that can be parsed and executed dynamically. Inline programs have the
advantage of simplicity by not requiring a separate program file to manage. The
first REXX function could also just as well have been handled inline.
A function must be defined before it is called.
118
Unleashing AS/400 Applications on the Internet
4.2.3 HTML INPUT Section
%{
**********************
%HTML (INPUT) {
<html>
<head>
<title>$(page_title)</title>
HTML Section: Input
************************%}
←Identifies the name of this HTML section
←Note the variable substitution from
the define section.
</head>
<body>
<h1>Input Form</h1>
<hr>
Today is @today()
←This line contains a call to the
REXX function today.
Type some data to pass to a REXX program:
<FORM METHOD=″post″ ACTION=″output″> ←When this form is
submitted, the ″output″
HTML section is called.
<INPUT NAME=″input_data″
←″input_data″ is now an implicitly defined
TYPE=″text″ SIZE=″30″>
variable that can be referenced elsewhere in
this macro. It is initialized to whatever
the user types into the input field.
We will use it in the output section .
<p>
<INPUT TYPE=″submit″ VALUE=″Enter″>
</FORM>
<hr>
<p>
[
<a href=″/″>Home page
]
</body>
</html>
%}
←Closes the HTML section
Figure 46. HTML Section: Input
This section contains the HTML for a simple form with one input field. The entire
HTML section is surrounded by the HTML section identifier, %HTML (INPUT) { ...
% } . INPUT identifies the name of this section. You can give it any name (an
enhancement from DB2WWW Connection, which only allowed INPUT and
REPORT) . The HTML <title> statement contains an example of macro variable
substitution. The contents of the variable ″page_title″ are substituted into the
title of the form.
This section also has an example of a function call. The expression @today() is
a call to function ″today″. This function is defined in the FUNCTION definition
section that is described in Section 4.2.2, “Function Definition Section” on
page 118. The result of the ″today″ function (today′s date) is inserted into the
HTML text in the same location that the @today() expression is located.
The ACTION parameter of the FORM statement is an example of navigation
between HTML sections or between macros. Referencing the name of another
section in an ″ACTION″ parameter accesses that section when the form is
submitted. Any input data is passed to the new section as implicit variables.
This is true of the single input field defined on this form. When the form is
Chapter 4. Net.Data Implementation
119
submitted, data typed into this field is passed to the ″output″ section in the
variable ″input_data″.
You can access sections in other macros with a relative reference. For example,
A C T I O N = ″../othermacro.mbr/main″ accesses the ″main″ HTML section in a
macro file called ″othermacro.mbr″ on the AS/400 system. Again, any data typed
into the form is passed to this macro in the implicit variable ″input_data″.
Notice again the simplicity of writing a macro. There is no need to deal with
environment variables to receive input data as you do with CGI-BIN programs.
That processing is handled for you automatically by Net.Data. You only need to
reference the variable names.
Figure 47. Browser View of Input HTML
120
Unleashing AS/400 Applications on the Internet
4.2.4 HTML OUTPUT Section
%{ **********************
HTML Section: Output
************************%}
%HTML (OUTPUT) {
<html>
<head>
<title>$(page_title)</title> ←More substitution
</head>
<body>
<h1>Output Page</h1>
<hr>
<p>@rexx1(input_data) ←This line contains a call to function rexx1
passing the argument ″input_data″
<p>
<hr>
<p>
[
<a href=″/″>Home page |
<a href=″input″>Previous page
]
</body>
</html>
%}
Figure 48. HTML Section: Output
The same as the INPUT section, this section is standard HTML enhanced with
macro statements to substitute variables and a function call. Again, the
″page_title″ variable is substituted into the title statement. And, as before, this
section contains a function call. In this case, it calls the function ″rexx1″ and
passes to it the contents of the variable ″input_data″ that it received from the
INPUT form. You can pass any number of variables to and from a function. The
function definition determines the number of variables passed and their type.
This is the output as displayed in the browser.
Chapter 4. Net.Data Implementation
121
Figure 49. Browser View of HTML Output
4.3 Generating HTML in a Web Macro
The ability to access data and applications and to present that information as
HTML on a Web browser is what makes Net.Data so powerful.
4.3.1 HTML Blocks
The %HTML block and the functions that get invoked from the %HTML block are
the sections of the Web macro that generate HTML output to the browser.
Whenever Net.Data is invoked, an HTML block must be specified. What is
contained in this block controls the rest of the Net.Data invocation.
Any valid HTML may appear in an %HTML block. In addition, %INCLUDE
statements, function calls, and variable references can be in an %HTML block.
A common use of %HTML blocks in a Web macro is shown by this sample Web
macro:
%{ **********************
Define Section
%DEFINE{ DATABASE=″*LOCAL″
TABLE=″ASOLIB.HARDWARE″
%}
************************%}
%{ **********************
HTML Section: Input
************************%}
%HTML(INPUT){
<H1>Hardware Query Form</H1>
<HR>
<FORM METHOD=″POST″ ACTION=″OUTPUT″>
<dl>
<dt>What hardware do you want to list?
<dd><input type=″radio″ name=″hdware″ value=″ ′ MON′ ″ checked>Monitors
<dd><input type=″radio″ name=″hdware″ value=″ ′ PNT′″>Pointing devices
<dd><input type=″radio″ name=″hdware″ value=″ ′ PRT′″>Printers
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Unleashing AS/400 Applications on the Internet
<dd><input type=″radio″ name=″hdware″ value=″ ′ SCN′″>Scanners
</dl>
<input type=submit value=″Submit″>
</FORM>
%}
%FUNCTION(DTW_SQL) queryHardware() {
SELECT MODNO, COST, DESCRIP FROM $(TABLE) WHERE TYPE=$(hdware)
%REPORT{
<B>Here is the list you requested:</B><BR>
%ROW{
<HR>
$(N1): $(V1)
$(N2): $(V2)
<P>
$(V3)
%}
%}
%}
%{ **********************
HTML Section: Output
************************%}
%HTML(OUTPUT){
<H1>Hardware Query Results</H1>
<HR>
@queryHardware()
<HR>
<A href=″http://www.ibm.com/cgi-bin/db2www/equiplst.mbr/input″>List of hardware</A>
%}
The Web macro might initially be invoked from an anchor reference such as the
following example:
<A href=″http://www.ibm.com/cgi-bin/db2www/equiplst.mbr/input″>List of hardware</A>
When the application user clicks on this reference, Net.Data is invoked and
Net.Data parses the Web macro file. When it gets to the %HTML block specified
on the invocation (in this case, the %HTML(INPUT) block), it begins to process
the text inside the block. Anything that is not recognized by Net.Data as a Web
macro language construct is assumed to be HTML and is sent to the browser to
be displayed. After a selection is made and the Submit button pressed, the
ACTION part of the HTML < F O R M > element is executed, which specifies a call
to the Web macro′s %HTML(OUTPUT) block. The %HTML(OUTPUT) block is
processed just as the %HTML(INPUT) block was. All data up to the
@queryHardware() function call is output to the browser as HTML.
The queryHardware() function call is processed, which, in turn, invokes the SQL
%FUNCTION block. After the $(hdware) variable reference is replaced in the
SQL statement with the value returned in the input form, the query is executed.
At this point, Net.Data again starts sending HTML to the browser, displaying the
results of the query according to the HTML specified in the %REPORT block.
After the %REPORT block processing is done, we return again to the
%HTML(OUTPUT) block and finish processing by sending out the remaining
HTML specified after the @queryHardware() function call.
Only one %HTML block is processed for each Net.Data invocation. However, by
using HTML anchor references and forms, it becomes easy to let the end-user
start another invocation of Net.Data on another %HTML block, all controlled by
you.
Chapter 4. Net.Data Implementation
123
4.4 Web Macro Functions
This section discusses the Net.Data macro function definitions.
4.4.1 Define Functions
You can define your own functions or use Net.Data′s library of built-in functions.
For functions that are not built-in, use a %FUNCTION block to define the function
in the Web macro. The syntax is shown here:
%FUNCTION(type) function-name([usage parameter, ...]
) [RETURNS(return-var)] {
executable-statements
[report-block]
[message-block]
%}
Table 10 (Page 1 of 2). Net.Data Function Definitions
Implicit Function Definitions
Type
Identifies a language environment that is configured in the
initialization file. The language environment invokes a specific
language processor (which processes the executable
statements) and provides a standard interface between
Net.Data and the language processor.
Function name
This is the name of the %FUNCTION block. The %FUNCTION
block is executed by referencing this name elsewhere in the
Web macro preceded by an at (@) sign.
Multiple %FUNCTION blocks can exist with the same name.
They must all have identical parameter lists. When the
function is called, all %FUNCTION blocks with the same name
are executed in the order that they are defined in the Web
macro.
Usage
IN, OUT, or INOUT. This indicates whether the parameter is
passed into or received back from the %FUNCTION block, or
both. The usage type applies to all of the following parameters
in the parameter list until changed by another usage type. The
default type is IN.
Parameter
The name of a locally scoped variable that is replaced with the
value of a corresponding argument specified on a function call.
Parameter references (for example, $(parm1) ) in the
executable statements or report section are replaced with the
actual value of the parameter. In addition, parameters are
passed to the language environment and are accessible to the
executable statements using the natural syntax of that
language or as environment variables. Parameter variable
references are not valid outside the %FUNCTION block.
You can also pass implicit parameters on a function call of a
type you specify. You must define the parameters in the
ENVIRONMENT statement in the initialization file. Parameters
can only be specified once in the parameter list.
Return v a r
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Unleashing AS/400 Applications on the Internet
Specify this parameter after the RETURNS keyword. It
identifies a special OUT parameter. The value of the return
variable is assigned to the function call and replaces the
function call in the Web macro processing. If you do not
specify the RETURNS clause, the value of the function call is
the null string if the return code from the call to the language
environment is 0 or the value of the return code otherwise.
Table 10 (Page 2 of 2). Net.Data Function Definitions
Implicit Function Definitions
Executable
statements
After the variables are substituted and the function calls are
processed, these statements are passed to the specified
language environment for execution. Each language
environment processes the statements differently.
Report_block
See Section 4.5, “Report Blocks” on page 134.
Message block
See Section 4.5.1, “Message Blocks” on page 136.
You need to define functions at the outermost Web macro layer before they are
called in the Web macro.
Besides letting you define your own %FUNCTION blocks, Net.Data also has a
library of built-in functions. You do not need to define these functions before you
reference them. Just call them from a Web macro anywhere a function call can
be made. See Section 4.4.3, “Net.Data Built-In Functions” on page 129 for a list
of these functions.
4.4.2 Calling Functions
You invoke a function from a Web macro using the at ( @) character followed by
a %FUNCTION block name:
@function_name([ argument,... ])
Table 11. Net.Data Calling Functions
Function_name
This is the name of the %FUNCTION block to invoke. The
function must already be defined in the Web macro unless this
is a built-in function.
Argument
This is the name of a defined variable or a literal character
string. Arguments on a function call are matched up with the
parameters on a %FUNCTION block and each parameter is
assigned the value of its corresponding argument for the
duration of the %FUNCTION block. The arguments must be
the same number and type as the corresponding parameters.
When a %FUNCTION block is invoked, Net.Data proceeds this way:
1. Net.Data matches up all of the arguments on the function call with the
parameters from the %FUNCTION block. If the number or usage type of the
variables do not match, an error occurs.
2. A set of variables is built from all of the function parameters specified in the
%FUNCTION block and the arguments specified in the ENVIRONMENT
statement in the initialization file. There are two distinct sets of variables at
this step: the global set, consisting of all variables that have been defined in
the Web macro so far and the local set just built for the function.
3. Variable references in the executable text of the %FUNCTION block are
replaced with the actual value of the variable by looking for the variable in
the local variable set and then in the global variable set. If the variable
exists in both sets (for example, it was specified as a function parameter and
on a previous %DEFINE), the local set takes precedence.
4. Function calls in the executable text of the %FUNCTION block are processed.
The context of the function call does not matter to Net.Data within executable
text. For example, if your executable text contains conditional logic, and a
Chapter 4. Net.Data Implementation
125
function call exists within a particular leg of that conditional logic, it is
processed by Net.Data regardless of the logic. This is because Net.Data
processes the function call before the executable text.
5. The variables in the local set are passed to the language environment along
with the text of the executable statements. The language environment is
responsible for passing the IN and INOUT variables to the language
processor, interpreting the executable statements or invoking the language
processor to execute the statements and retrieving any OUT or INOUT
variables back from the language processor when the program completes.
6. When the language environment returns to Net.Data, any OUT or INOUT
parameters are obtained from the parameter list and their values are used to
replace the values of their corresponding arguments in the local and global
variable sets. If there is a RETURNS clause, the value of the return variable
is saved with the %FUNCTION block information so that it can be used to
replace the function call in the Web macro expansion.
The rules for using and modifying variables from a %FUNCTION block in a
function call can be summarized as follows:
1. All variables, both globally-defined and function parameters, are used to
perform variable substitution on the executable statements before invoking
the function.
2. Only IN or INOUT parameters are passed to the language environment.
3. Only OUT or INOUT parameters can be modified by the function.
4. All variables, both globally-defined and function parameters, are used to
perform variable substitution on the report section of the %FUNCTION block
after invoking the function.
When %MESSAGE block and %REPORT block processing is complete, the value
of the function call is used to replace the function call in the Web macro.
4.4.2.1 Calling High-Level Language Programs
This example shows you how to call an RPG program from Net.Data. The same
method is used to call other high-level language programs on the AS/400
system. To pass parameters from Net.Data to your high-level language program,
you need to use the same API (Application Programming Interface) you use for
CGI-BIN programs. This means using the API Get Environment Variables
(QtmhGetEnv) to get Variables from Net.Data and Write to Standard out
(QtmhWrStout) to return a text buffer to Net.Data. For a more detailed
discussion about these APIs, see Section 3.9, “Programming CGI-BIN with ILE
RPG/400 and ILE COBOL/400” on page 82.
Returning Variables to Net.Data
Currently it is not possible to return environment variables to Net.Data from
RPG or COBOL. One solution for this is to call a C program to return the
environment variables to Net.Data. A new API, QtmhPutEnv, is planned for
V4R1 and will allow RPG or COBOL programs to return varibles to Net.Data.
This is the listing of the RPG program that we call from the Net.Data macro.
This simple program uses the API QtmhGetEnv to read the input from the
browser. We add a little constant text to the output buffer and use the API
QtmhWrStout to return the modified string to the browser.
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Unleashing AS/400 Applications on the Internet
0001.00
0002.00
0003.00
0004.00
0005.00
0006.00
0007.00
0008.00
0009.00
0010.00
0011.00
0012.00
0013.00
0014.00
0015.00
0016.00
0017.00
0018.00
0019.00
0020.00
0021.00
0022.00
0023.00
0024.00
0025.00
0026.00
0027.00
0028.00
0029.00
0030.00
0031.00
0032.00
0033.00
0034.00
0035.00
0036.00
0037.00
0038.00
0039.00
0040.00
0041.00
0042.00
0043.00
0044.00
0045.00
* Data structure for error reporting. Copied from QSYSINC/QRPGLESRC(QUSEC)
deol
c
x′ 1 5 ′
dtxt
c
′ Text added to the buffer′
DQUSEC
DS
D*
Qus EC
D QUSBPRV
1
4B 0 INZ(16)
D*
Bytes Provided
D QUSBAVL
5
8B 0
D*
Bytes Available
D QUSEI
9
15
D*
Exception Id
D QUSERVED
16
16
*****************************************************************************************
*These are for the APIEnVar
DENBuff
S
1024A
INZ
Return area for API
DENBuffLn
S
9B 0 INZ(1024)
Ln of return area
DENActLn
S
9B 0 INZ
Act Ln of ret data
DENVarName
S
64A
INZ
Name of Env Var
DENVarLn
S
9b 0 INZ
Ln of EnVar name
*These are used for APIStdOut
DOutBuff
S
100A
Area for output
DOutBuffLn
S
9B 0 INZ(100)
Length of Output ar
*********************************************************************************************
C
MOVEL
′ parm1′
ENVarName
C
Z-ADD
05
ENVarLn
C
CALLB
′ QtmhGetEnv′
C
parm
ENBuff
Input buffer
C
parm
ENBuffLn
Input buffer max ln
C
parm
ENActLn
StdIn actual length
C
parm
ENVarName
C
parm
ENVarLn
C
parm
QUSEC
**********************************************************************************************
* Upon return, your Query_String data is in ENBuff with the length
* of the data returned in ENActLn
* Move this data to the DBCvt parms
C
eval
outbuff = %subst(enbuff:1:enactln)+txt+eol
C
′ ′
checkr
outbuff
outbuffln
C
callb
′ QtmhWrStout′
C
parm
OUTBuff
Output buffer
C
parm
OUTBuffLn
Output buffer len h
C
parm
QUSEC
**********************************************************************************************
C
eval
*inlr = *on
C
return
Figure 50. RPG Program Called from Net.Data
This macro calls the RPG program and returns the result to the browser.
%{********* Function **********%}
%FUNCTION (DTW_SYSTEM) rpgpgm (in parm1) {
%EXEC{ /QSYS.LIB/NDCGI.LIB/rpgpgm.pgm %}
%}
%{********* INPUT *************%}
%HTML (input) {
<HTML>
<FORM METHOD=″POST″ ACTION=″OUTPUT″>
Enter input for the RPGPGM here:<br>
<INPUT TYPE=text NAME=prod>
<INPUT TYPE=submit>
</FORM>
</HTML>
%}
%{********* REPORT ************%}
Chapter 4. Net.Data Implementation
127
%HTML (OUTPUT) {
<HTML>
We will now call the RPG program and pass the parameter: <P>
$(prod) <P>
<HR>
The output of the RPG program is:<P>
@rpgpgm(prod)
</HTML>
%}
This is the input window where you enter the value to be passed to the RPG
program.
Figure 51. RPG Program Input Window
When the user presses the ″Submit Query″ button, Net.Data parses the ″Report″
HTML section and runs the program RPGPGM.PGM, passing the value entered
in the ″INPUT″ HTML section and returns the modified value to the browser.
Figure 52. RPG Program Report Window
An alternative way to call a high level program and pass parameters is through
the REXX language environment as demonstrated with the following example
that calls the ″count″ RPG program from the code snippets page. To download
the count program, follow the link from the AS/400 Web Builders pages:
http://205.217.130.15/workshop/snippets/snippets.htm
or
http://www.as400.ibm.com/workshop/webbuild.htm
The ″count″ program allows you to use one program to add counters to multiple
pages within a Net.Data macro by passing a unique ″countname″ for each page
you want the counter on.
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Unleashing AS/400 Applications on the Internet
%{ **************
Define Section
********************%}
%DEFINE { countvalue=″0″ %}
%DEFINE { countname=″PGCNTR1″ %}
%{ ************** Function Definition Section ********************%}
%FUNCTION(DTW_REXX) CNTR2 (IN countname, INOUT countvalue)
{ ′ CALL PGM(CGIDEV/COUNT) PARM(&countname &countvalue)′ %}
%{ **********
HTML Section: Input
************************%}
%HTML (INPUT) {
<html>
<head>
<title>Counter</title>
</head>
<BODY>
@CNTR2(countname, countvalue)
This page has been viewed <b>$(countvalue)</b> times!
<p>
@DTW_ASSIGN (countname, ″PGCNTR2″ )
@CNTR2(countname, countvalue)
This page2 has been viewed <b>$(countvalue)</b> times!
</HTML>
%}
This macro puts two counters on one page. This may not be what you want!
However, it illustrates using the built-in function @DTW_ASSIGN to give the
value ″countname″ a new value that adds a record to the data file CGICOUNT
and returns the ″countvalue″ to the browser. Typically, you use the ″ % DEFINE {
c o u n t n a m e = ″PGCNTR1″ %} to change this value.
Figure 53. REXX Calls RPG Program COUNT
4.4.3 Net.Data Built-In Functions
Net.Data provides a large library of predefined functions for use within your
macros. The use of these functions can simplify the construction of your
dynamically created Web pages. The built-in functions fall into seven basic
groups.
1. General functions are a group of functions that Web builders can use to
develop Web pages that can change data and give access to some system
services (that is, date and time).
•
•
•
•
.
DTW_ADDQUOTE / DTW_rADDQUOTE / DTW_mADDQUOTE
DTW_DATE / DTW_rDATE
DTW_GETENV / DTW_rGETENV
DTW_GETINIDATA / DTW_rGETINIDATA
Chapter 4. Net.Data Implementation
129
•
•
•
•
•
DTW_HTMLENCODE / DTW_rHTMLENCODE
DTW_QHTMLENCODE / DTW_rQHTMLENCODE
DTW_SETENV / DTW_rSETENV
DTW_TIME / DTW_rTIME
DTW_URLESCSEQ / DTW_rURLESCSEQ
2. Math functions allow you to do math functions within the macro without the
need to call a high level language program. This simplifies the writing of the
Net.Data macro. The following math functions are currently supported.
•
•
•
•
•
•
•
•
DTW_ADD / DTW_rADD
DTW_DIVIDE / DTW_rDIVIDE
DTW_DIVREM / DTW_rDIVREM
DTW_FORMAT / DTW_rFORMAT
DTW_INTDIV / DTW_rINTDIV
DTW_MULTIPLY / DTW_rMULTIPLY
DTW_POWER / DTW_rPOWER
DTW_SUBTRACT / DTW_rSUBTRACT
3. String manipulation functions provide functions to modify character strings.
Net.Data supports the following functions:
•
•
•
•
•
•
•
•
•
•
•
•
•
DTW_ASSIGN
DTW_CONCAT, DTW_rCONCAT
DTW_DELSTR, DTW_rDELSTR
DTW_INSERT, DTW_rINSERT
DTW_LASTPOS, DTW_rLASTPOS
DTW_LENGTH, DTW_rLENGTH
DTW_LOWERCASE, DTW_rLOWERCASE, DTW_mLOWERCASE
DTW_POS, DTW_rPOS
DTW_REVERSE, DTW_rREVERSE
DTW_STRIP, DTW_rSTRIP
DTW_SUBSTR, DTW_rSUBSTR
DTW_TRANSLATE, DTW_rTRANSLATE
DTW_UPPERCASE, DTW_rUPPERCASE, DTW_mUPPERCASE
4. Word manipulation functions allow you to manipulate words in a character
string. The following functions are supported:
•
•
•
•
•
•
•
DTW_DELWORD, DTW_rDELWORD
DTW_SUBWORD, DTW_rSUBWORD
DTW_WORD, DTW_rWORD
DTW_WORDINDEX, DTW_rWORDINDEX
DTW_WORDLENGTH, DTW_rWORDLENGTH
DTW_WORDPOS, DTW_rWORDPOS
DTW_WORDS, DTW_rWORDS
5. Table manipulation functions allow you to manipulate tables and easily build
Web forms with dynamic data. These functions allow you to build select
blocks, radio buttons, and so on, and fill them automatically with data from
the AS/400 database. The table manipulation functions supported by
Net.Data are:
•
•
•
•
•
•
130
DTW_TB_DLIST
DTW_TB_DUMPH
DTW_TB_DUMPV
DTW_TB_HTMLENCODE
DTW_TB_INPUT_CHECKBOX
DTW_TB_INPUT_RADIO
Unleashing AS/400 Applications on the Internet
•
•
•
•
•
DTW_TB_INPUT_TEXT
DTW_TB_LIST
DTW_TB_SELECT
DTW_TB_TABLE
DTW_TB_TEXTAREA
6. Flat file interface functions are not currently supported on the AS/400 system.
It is planned that support for these functions will be included in a future
release of the operating system. As defined by Net.Data, the flat file
interface functions are:
•
•
•
•
•
•
•
•
•
•
DTWF_APPEND
DTWF_CLOSE
DTWF_DELETE
DTWF_INSERT
DTWF_OPEN
DTWF_READ
DTWF_REMOVE
DTWF_SEARCH
DTWF_UPDATE
DTWF_WRITE
7. Web registry functions are not currently supported on the AS/400 system. It
is planned that support for these functions will be included in a future
release of the operating system. As defined by Net.Data, the Web registry
functions are:
•
•
•
•
•
•
•
DTWR_ADDENTRY
DTWR_DELENTRY
DTWR_DELREG
DTWR_LISTREG
DTWR_LISTSUB
DTWR_RTVENTRY, DTWR_rRTVENTRY
DTWR_UPDATEENTRY
For detailed information on any of the built-in functions, you should see the
online Net.Data Reference Guide at
http://www.software.ibm.com/data/net.data/docs/dtwref.htm
4.4.4 Table Variables
The table variable defines a collection of related data within Net.Data. It
contains an array of identical records, or rows, and an array of column names
describing the fields in each row. A table is defined in the Web macro with a
statement such as this:
%DEFINE myTable=%TABLE(30)
The number following %TABLE is the limit on the number of rows this table can
contain. To specify a table with no limit on the number of rows, use the default
or specify ALL as shown in these examples:
%DEFINE myTable2=%TABLE
%DEFINE myTable3=%TABLE(ALL)
A table can be passed between functions by referring to the table variable
The individual elements of a table can be referred to in a %REPORT block
function. Table variables are usually used for output from an SQL function
input to a report, but you can pass them as IN, OUT, or INOUT parameters
Chapter 4. Net.Data Implementation
name.
of a
and
to any
131
non-SQL function. Tables can only be passed to SQL functions as OUT
parameters. A table can be represented graphically:
Figure 54. Net.Data Table View
The column names and field values in a table are addressed as array elements
with an origin index of 1 rather than the standard C and C++ language
convention of starting arrays at an index of 0.
4.4.5 Implicitly Defined Variables
Defining a table variable causes Net.Data to implicitly define two sets of
variables that you can use to refer to the column names and field contents of the
table. One set of these implicit variables is referred to in the %REPORT block of
a %FUNCTION block in a Web macro, and the other set is referred to in
programs called from language environments. You cannot refer to these
variables in any other section of the Web macro.
Table 12 (Page 1 of 2). Net.Data %REPORT Block
Implicit %REPORT Variables
132
N1,...N p
Where p is the column number. These variables contain the
column names.
N_ column-name
Where column-name is the value of one of the N p variables. If
it exists, this variable has the value column-name .
NLIST
This LIST variable is created by concatenating all of the
individual column names N p . The default separator for the list
variable is a space character, but this can be changed by
specifying it on a LIST define such as: %define %LIST ″; ] ″;
NLIST.
Unleashing AS/400 Applications on the Internet
Table 12 (Page 2 of 2). Net.Data %REPORT Block
Implicit %REPORT Variables
V1...V p
Where p is the column number. This variable contains the
value of the p th column in the current row. These variables
are only valid in a %ROW block of a %REPORT block and are
set to new values as each row is printed.
V_ column-name
Where column-name is the value of one of the N p variables.
This variable contains the value of the field in the current row
whose column name is column_name . These variables are
only valid in a %ROW block of a %REPORT block and are set
to new values as each row is printed.
VLIST
This %LIST variable is created by concatenating all of the
individual field values V p in the current row. The default
separator for this list variable is a space character, but this
can be changed by specifying it on a %LIST define. These
variables are only valid in a %ROW block of a %REPORT block
and are set to new values as each row is printed. This is most
useful for creating tables in HTML 3.0.
ROW_NUM
Contains the row number of the current row. After the %ROW
block has been processed, ROW_NUM contains the total
number of rows in the table. This variable is only valid in a
%ROW block of a %REPORT block and is set to a new value
as each row is printed.
NUM_COLUMNS
Contains the number of columns in the table.
TOTAL_ROWS
Contains the number of rows in the table.
The following variables can be used in a REXX program called by a function call
to a REXX %FUNCTION block.
Table 13. Net.Data REXX Language Environment Variables
Implicit REXX Language Environment Variables
T_ROWS
Where T is the table name. This variable contains the current
number of rows in the table.
T_COLS
Where T is the table name. This variable contains the current
number of columns in the table.
T_N. p
T is the table name and p is the column number. This variable
contains the name of the p th column.
T_V. i.p
T is the table name, i is the row number, and p is the column
number. This variable contains the value of the p th column of the
i th row in the table.
You can use the following variables in programs invoked by a function call to a
SYSTEM %FUNCTION block. These table variables are accessible as
environment variables.
Table 14 (Page 1 of 2). Net.Data SYSTEM Language Environment Variables
Implicit SYSTEM Language Environment Variables
T_ROWS
T is the table name. This variable contains the current number of
rows in the table.
T_COLS
T is the table name. This variable contains the current number of
columns in the table.
Chapter 4. Net.Data Implementation
133
Table 14 (Page 2 of 2). Net.Data SYSTEM Language Environment Variables
Implicit SYSTEM Language Environment Variables
T_N_ p
T is the table name and p is the column number. This variable
contains the name of the p th column.
T_V_ i_p
T is the table name, i is the row number, and p is the column
number. This variable contains the value of the p th column of the
ith row in the table.
4.5 Report Blocks
The %REPORT block is used to format and display data output from a
%FUNCTION block. This output is typically table data, although any valid
combination of HTML tags, macro variable references, and function calls may be
specified. A table name may be specified on the %REPORT block but is not
required. If a table name is not specified, the table data used is that of the first
output table in the parameter list of this %FUNCTION block. If no table was
specified on the %FUNCTION block, the default table data is used.
The %REPORT block is composed of three parts, each of which is optional:
1. Header: Contains HTML data displayed before table row data.
2. % R O W block: Contains HTML and table variables displayed once per row of
the table.
3. Footer: Contains data displayed after table row data.
If you do not want to display any table output from the %ROW block, just leave it
empty.
When Net.Data processes a %FUNCTION block, a call is made to a language
environment and data is returned. Net.Data processes the %REPORT block.
Inside the %REPORT block, several implicitly defined variables are made
available to you to access the data in the Web macro table that is used in the
report. These variables are described in Table 12 on page 132.
Header and footer information is not explicitly specified as such in a %REPORT
block. Net.Data simply assumes that everything it finds before a %ROW block is
header information and everything it finds after the %ROW block is footer
information. As with the %HTML block, the Web macro processor treats
everything in the header, %ROW block, and footer sections as HTML and sends
that data to the browser unless it recognizes the data as a Web macro construct.
1. The header information is processed and displayed once.
2. %ROW block information is processed once for each row in the table.
3. The footer information is processed and displayed once.
You can decide not to display any data by specifying an empty %REPORT block
this way:
%REPORT {
%}
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Unleashing AS/400 Applications on the Internet
Or you can display a default report by omitting the %REPORT block. The
following example shows how a default report might look for a table with five
rows and five columns:
COL1
| COL2
| COL3
| COL4
| COL5
|
-------------------------------------------------( 1 1 ) | ( 1 2 ) | ( 1 3 ) | ( 1 4 ) | ( 1 5 ) |
-------------------------------------------------( 2 1 ) | ( 2 2 ) | ( 2 3 ) | ( 2 4 ) | ( 2 5 ) |
-------------------------------------------------( 3 1 ) | ( 3 2 ) | ( 3 3 ) | ( 3 4 ) | ( 3 5 ) |
-------------------------------------------------( 4 1 ) | ( 4 2 ) | ( 4 3 ) | ( 4 4 ) | ( 4 5 ) |
-------------------------------------------------( 5 1 ) | ( 5 2 ) | ( 5 3 ) | ( 5 4 ) | ( 5 5 ) |
-------------------------------------------------You can use the DTW_DEFAULT_REPORT special variable to enable or disable
default reporting when no %REPORT block is specified. If
DTW_DEFAULT_REPORT is set to ″ NO ″, default reporting is disabled. If
DTW_DEFAULT_REPORT is set to ″ YES″, default reporting is enabled. The
default is ″YES″.
DTW_DEFAULT_REPORT only applies if no %REPORT block is defined.
Also, you have the choice of having the default report generated using HTML
tables. To enable this, the DTW_HTML_TABLE special variable must be set to
″ YES″. The default is not to use HTML table tags.
This example shows how you can customize report formats using special
variables and HTML tags. It displays the names, phone numbers, and Fax
numbers from the table CustomerTbl .
%FUNCTION(DTW_SQL) custlist() {
SELECT Name, Phone, Fax FROM CustomerTbl
%REPORT{
Phone Query Results:<BR>
===================== <BR>
%ROW{
Name: <B>$(V1):</B><BR>
Phone: $(V2)<BR>
Fax: $(V3)<BR>
------------------------------ <BR>
%}
Total records retrieved: $(ROW_NUM)
%}
%}
The resulting report looks similar to this:
Phone Query Results:
====================
Name: Doen, David
Phone: 422-245-1293
Fax: 422-245-7383
-----------------------------Name: Williamson, Jack
Phone: 955-768-3489
Fax: 955-768-3974
Chapter 4. Net.Data Implementation
135
-----------------------------Total records retrieved: 2
Net.Data generated the report by:
1. Printing Phone Query Results , once at the beginning of the report.
2. Giving the variables $(V1) , $(V2) , and $(V3) the values for Name, Phone, and
Fax respectively for each row as it is retrieved.
3. Drawing a line after each row retrieved to help readability.
4. Printing the string Total records retrieved: and the value for $(ROW_NUM)
once at the end of the report.
4.5.1 Message Blocks
The %MESSAGE block lets you determine how to proceed after a function call
based on the success or failure of the function call, and lets you display
information to the caller of the function.
Net.Data sets RETURN_CODE, an implicit variable, for each function call.
RETURN_CODE is set to the return code of the call to the language environment
the function calls. When the function call is completed, the %MESSAGE block
uses the value of RETURN_CODE to determine how to proceed. A %MESSAGE
block consists of a series of message statements, each statement specifying a
return code value, message text, and an action to take. The syntax of a
%MESSAGE block is shown here:
%MESSAGE {
[return_code : message_text [ : action]]
.
.
.
%}
Table 15 (Page 1 of 2). Message Block Definitions
return_code
Message_text
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Unleashing AS/400 Applications on the Internet
Any positive or negative number. If the RETURN_CODE
variable value matches this value, the remaining information
in the message statement is used to process the function call.
There are three special values that can be specified for
return_code :
•
+ d e f a u l t : If RETURN_CODE is greater than 0 and an exact
match is not specified, the information in this message
statement is used to process the function call.
•
-default: If RETURN_CODE is less than 0 and an exact
match is not specified, the information in this message
statement is used to process the function call.
•
default: If RETURN_CODE does not equal 0 and an exact
match is not specified and the + d e f a u l t (for
RETURN_CODE greater than 0) or -default (for
RETURN_CODE less than 0) value is not specified, the
information in this message statement is used to process
the function call.
This string is sent to the Web browser if the RETURN_CODE
matches the return_code value in this message′s message
statement.
Table 15 (Page 2 of 2). Message Block Definitions
Action
This determines what action Net.Data takes if the
RETURN_CODE matches the return_code in this message
statement. There are two valid values:
•
exit: Net.Data exits immediately.
•
continue: Net.Data continues processing the Web macro in
the function block it was calling.
This is optional. If no action is specified, the default is exit .
A %MESSAGE block can have a global or a local scope. If the %MESSAGE
block is defined in a %FUNCTION block, it is scoped locally to that %FUNCTION
block. If it is specified at the outermost macro layer, it has global scope and is
active for all function calls executed in the Web macro. If you defined more than
one global %MESSAGE block, the last one defined is active.
Net.Data uses these rules to process a RETURN_CODE from a function call:
1. Check local %MESSAGE block for an exact match; exit or continue as
specified.
2. If RETURN_CODE is not 0, check local %MESSAGE block for + d e f a u l t or
-default , depending on the sign of RETURN_CODE; exit or continue as
specified.
3. If RETURN_CODE is not 0, check local %MESSAGE block for default ; exit or
continue as specified.
4. Check global %MESSAGE block for an exact match; exit or continue as
specified.
5. If RETURN_CODE is not 0, check global %MESSAGE block for + d e f a u l t or
-default , depending on the sign of RETURN_CODE; exit or continue as
specified.
6. If RETURN_CODE is not 0, check global %MESSAGE block for default ; exit or
continue as specified.
7. If RETURN_CODE is not 0, issue Net.Data internal default message and exit.
Here is an example. Assume the following %MESSAGE blocks are defined in
your Web macro:
Chapter 4. Net.Data Implementation
137
%{
global message block %}
%MESSAGE {
-100
: ″return code -100 message″
: exit
100
: ″return code 100 message″
: continue
+default : { This a long message that spans more
than one line. You can use HTML tags, including
anchors and forms, in this message also. %}
: continue
%}
%{ local message block inside a %FUNCTION block %}
%FUNCTION(DTW_REXX) my_function() {
%EXEC { my_command.cmd %}
%MESSAGE {
-100
: ″return code -100 message″
: exit
100
: ″return code 100 message″
: continue
-default : { This is a second long message that spans more
than one line. You can use HTML tags, including
anchors and forms, in this message. %}
: exit
%}
%}
Figure 55. Message Block Macro
If my_function() returns with RETURN_CODE set to 50, Net.Data processes in this
order:
1. Check for an exact match in the local %MESSAGE block. (There is none.)
2. Check for a + d e f a u l t in the local %MESSAGE block. (There is none.)
3. Check for a default in the local %MESSAGE block. (There is none.)
4. Check for an exact match in the global %MESSAGE block. (There is none.)
5. Check for a + d e f a u l t in the global %MESSAGE block. (There is one.)
Now that Net.Data found a match, it sends the message text to the Web browser
and checks the requested action. Because continue is specified, Net.Data
continues to process the Web macro after printing the message text.
For example, if error 100 is found during processing with the %MESSAGE block
in the example, output from a program can look similar to this:
.
.
.
11 November
13 November
19 November
return code
22 November
1996
1996
1996
100 message
1996
Total:
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$245.45
$623.23
$ 83.02
$ 42.67
$994.37
4.6 Language Environments
Net.Data is designed to allow new language and database interfaces to be added
in a ″pluggable″ fashion. These language environments are accessed as service
programs. The name of the service program is configured in the Net.Data
initialization file and associated with a language environment name. Each
language environment must support a standard set of interfaces defined by
Net.Data.
Net.Data for OS/400 provides the following language environments:
REXX
Allows external REXX programs or inline (REXX statements in a Web
macro function block) to be interpreted by the REXX interpreter.
SQL
Allows SQL statements to be processed by DB2.
System Allows external programs (C, RPG, COBOL) to be run.
The following sections describe the language environments previously listed.
4.6.1 REXX (DTW_REXX) Language Environment
The REXX language environment can interpret internal REXX programs that are
specified in a %FUNCTION block of the Web macro, or it can execute external
REXX programs stored in a separate file. Some of the characteristics of the
REXX language environments are:
•
The QREXX() REXX application program interface (API) is used by the
language environment to start the REXX interpreter for a REXX program.
•
The QREXVAR() REXX API is used by the REXX language environment to
pass data to a REXX program and to read data from a REXX program. Thus,
REXX programs can directly manipulate the Net.Data parameter variables
specified in a %FUNCTION block.
•
The REXX language environment starts the REXX interpreter in the default
command environment, COMMAND (the CL command environment). If you
want to run another command environment, such as EXECSQL (SQL
environment), CPICOMM (CPI communications environment), or a
user-defined language environment, you need to specify the language
environment in the REXX program using the ADDRESS built-in REXX function.
•
The REXX language environment requires external REXX programs to reside
in the QSYS.LIB file system.
•
The QTMHHTP1 user profile must have the proper authority to access and
read the file that contains the external REXX program in addition to any
resources that a REXX program uses.
Calls to external REXX programs are identified in a %FUNCTION block by a
statement of the form:
%EXEC{ REXX-file-name [optional parameters] %}
The following simple example shows a macro named REXXM with both an
internal REXX program and a reference to an external REXX program:
Chapter 4. Net.Data Implementation
139
%define a = ″3″
%define b = ″0″
%function(DTW_REXX) func1(IN inp1, OUT outp1) {
%EXEC{
/QSYS.LIB/REXX.LIB/REXXSRC.FILE/TREXX.MBR
%}
%}
%function(DTW_REXX) func2(IN inp1, OUT outp1) {
outp1 = 2*inp1
%}
%HTML(REPORT) {
@func1(a, b)
b=$(b)
@func2(a, b)
b=$(b)
%}
Figure 56. Macro REXXM
In the example, @func1 results in the REXX program TREXX.MBR being
interpreted by the REXX interpreter, and @func2 results in the REXX interpreter
interpreting the statement ″outp1 = 2*inp1″. In both cases, the REXX variable
pool is set so that the REXX interpreter can access variables ″a″ and ″b″.
This is an example URL that references the macro, assuming that:
•
The macro is located in the /WWW/macro directory.
•
The HTTP server has been configured to call the Net.Data CGI-BIN program
DB2WWW.
•
The user profile that CGI-BIN programs run under (QTMHHTP1) has been
given authority to access the macro file and the file containing the REXX
program.
http://hostname/cgi-bin/db2www/WWW/macro/REXXM/report
If you run this macro with the contents of the TREXX.MBR as shown:
Columns . . . :
1 80
SEU==>
FMT ** ...+... 1 ...+... 2 ...+... 3 ...+... 4 .
*************** Beginning of data ********
0001.00 outp1 = 3*inp1
****************** End of data ***********
Figure 57. REXX Source of TREXX.MBR
The output to the browser is:
b=9 b=6
If you did not create a Net.Data initialization file, the REXX language environment
is enabled by default. If you create an initialization file and you want to use the
REXX language environment, the following configuration statement must be in
the initialization file:
ENVIRONMENT(DTW_REXX) /QSYS.LIB/QTCP.LIB/QTMHREXX.SRVPGM ( )
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Unleashing AS/400 Applications on the Internet
4.6.2 SQL (DTW_SQL or SQL) Language Environment
The SQL language environment is used to execute SQL statements using DB2.
Some of the characteristics of the SQL language environments include:
•
The SQL language environment requires that a directory entry for the local
database is in the relational database directory (that is, a directory entry with
a remote location of *LOCAL). An entry can be added by using the Add
Relational Database Directory Entry (ADDRDBDIRE) command.
•
Any valid SQL statement can be passed to the SQL language environment.
The SQL statements must be valid DB2 for OS/400 commands.
•
SQL or system naming mode can be used. SQL naming mode is the default.
SQL naming mode uses a period when naming the tables.
Library.Table
System naming mode uses the standard slash.
Library/Table
If system naming mode is desired, insert the following line in the Net.Data
initialization file:
DTW_SQL_NAMING_MODE=SYSTEM_MODE
You can also set DTW_SQL_NAMING_MODE to SQL_MODE, which is the
same as the default of SQL naming mode.
When a connection is made to a remote AS/400 system, the SQL Call Level
Interface looks for an *SQLPKG object in library QGPL with the name of
QSQCLIPKG. If it exists, it is used, but if it does not exist it is created. This
SQL package contains all the rules by which the native SQL is accessed.
Therefore, the first connection′s attributes set the rules that all subsequent
connections must follow. The contents of the QGPL/QSQCLIPKG contains
the following information.
5716SS1 V3R6M0 950929
Print SQL information
Object name...............QGPL/QSQCLIPKG
Object type...............*SQLPKG
CRTSQL***
PGM(QGPL/QSQCLIPKG)
SRCFILE(*)
SRCMBR(*)
COMMIT(*CHG)
OPTION(*SQL *PERIOD)
TGTRLS(*PRV)
ALWCPYDTA(*OPTIMIZE)
CLOSQLCSR(*ENDPGM)
RDB(*NONE)
DATFMT(*ISO)
TIMFMT(*ISO)
ALWBLK(*ALLREAD)
DLYPRP(*NO)
DYNUSRPRF(*USER)
SRTSEQ(*HEX)
LANGID(
)
RDBCNNMTH(*RUW)
TEXT(′
′)
DECLARE SQLCURSOR000000001 CURSOR FOR SQLSTATEMENT000001
Figure 58. Contents of QGPL/QSQCLIPKG
Chapter 4. Net.Data Implementation
141
Naming Mode Considerations
If you set the DTW_SQL_NAMING_MODE to conflict with the naming mode
in an existing QGPL/QSQCLIPKG on a remote AS/400 system, the SQL
statement in the Web macro ends with an SQLCODE of -5016. To avoid
this, select a naming mode and stick with it. If the object
QGPL/QSQCLIPKG conflicts with the naming mode you have chosen,
delete it and issue the Net.Data request again. A new QGPL/QSQCLIPKG
is created with the naming mode option you require.
•
Concurrent connections to the same remote database are not allowed. If a
connection exists to a remote database using one user ID (the LOGIN SQL
language environment parameter) and another request is made to connect to
the same remote database using a second user ID, the SQL language
environment must first disconnect the existing connection, do a commit, and
reestablish the connection using the ″new″ user ID and password. The
reason that the commit is required is that if the connection is broken, there
is no way that a rollback can be accomplished in case of an error later in the
macro.
This example shows the parameters that need to be defined in the macro to
connect to a remote database. The database that you are connecting to
must be defined in the ″Relational Database Directory″ using the
WRKRDBDIRE (Work with Relational Database Directory Entries) command to
add, change, or remove entries in the directory.
%define{
DATABASE=″SYSTEM05″
LOGIN=″USERID2A″
PASSWORD=″HX1IMU″
TABLE=″AS0219R.BRANDS″
Mytable=%TABLE(ALL) %}
The database ″SYSTEM05″ has been added to the Relational Database
directory on the local AS/400 system. We can connect with the remote
database ″SYSTEM05″ (in this case, it is another AS/400 system). We pass
the USERID of ″USERID2A″ and the PASSWORD ″HX1IMU″. We return all
rows of the query from the file ″BRANDS″ in library ″AS0219R″ to the
Net.Data table ″Mytable″. More explanations of all the possible ″defines″ are
explained later in this chapter.
This does not pose a problem if you are using
″TRANSACTION_SCOPE=SINGLE″. If you use
″TRANSACTION_SCOPE=MULTIPLE″ (the default) and the ″new″ user ID
differs from the one used to establish the database connection to the remote
system, the SQL language environment automatically rolls back and an
SQL_CODE of -752 is returned, which indicates that the connection cannot be
changed.
142
•
Up to 50 databases can be accessed either local or remote. The connections
to the databases are kept active by the SQL language environment for the
life of the HTTP server job that Net.Data is running under. This results in fast
database access after the initial connection to the database.
•
When the SQL language environment establishes a connection to a remote
system, it associates a user ID with the connection. If, on a subsequent
Net.Data query, the user ID does not match those associated with the
connection, the connection is ended and a new connection to the database is
established (this only occurs if transaction scope is SINGLE).
Unleashing AS/400 Applications on the Internet
•
If a language environment is created that uses the database access class
library or the SQL call level interface and the language environment is
referenced in a macro, the SQL language environment cannot be used.
•
The QTMHHTP1 user profile must have the proper authority to access the
database on the machine where the HTTP server resides. For remote
databases, the user ID and password is used to determine what database
resources can be accessed.
Performance Tip
If performance is a concern, Web macro writers should hard code or use
the same user ID when issuing SQL statements to a remote database.
For local database access, the user ID and password are ignored.
•
SQL statements cannot be passed to the SQL language environment on an
%EXEC statement.
The following simple example shows a macro named SQLM that issues a single
SQL command:
%define
DATABASE=″HOSTNAME″
%FUNCTION(DTW_SQL) sql1 () {
select * from custinfo.customer
%}
%HTML(REPORT) {
@sql1()
%}
Figure 59. Simple SQL Command Function
This is an example URL that references the macro, assuming that:
•
The macro is located in the /WWW/macro directory.
•
The HTTP server has been configured to call the Net.Data CGI-BIN program
DB2WWW.
•
QTMHHTP1 has been given authority to access the macro file and table that
the SQL command reads.
http://hostname/cgi-bin/db2www/WWW/macro/SQLM/report
If you did not create a Net.Data initialization file, the SQL language environment
is enabled by default. However, if you create an initialization file, and you want
to use the SQL language environment, the following configuration statement
must be in the initialization file:
ENVIRONMENT(DTW_SQL) /QSYS.LIB/QTCP.LIB/QTMHSQL.SRVPGM
( IN DATABASE, LOGIN, PASSWORD, TRANSACTION_SCOPE, SHOWSQL,
DB_CASE, OUT DTWTABLE, SQL_CODE )
The text of this environment statement must all be on one line in the initialization
file. It is shown here divided between multiple lines for readability.
The SQL language environment parameters in the preceding configuration
statement are passed to the language environment and are described in the
following list:
Chapter 4. Net.Data Implementation
143
•
DATABASE: The SQL language environment establishes a connection (if a
connection has not already been established) to the database specified in
this variable. The following example shows how this variable can be set in a
Web macro:
%DEFINE DATABASE=″HOSTNAME″
•
LOGIN and PASSWORD : If the DATABASE parameter references a remote
database, the user ID and password specified in the LOGIN and PASSWORD
variables are used when connecting to a database. These parameters are
ignored when accessing the local database, and the user profile that CGI-BIN
programs run under (TMHHTP1) must be given access to any files that are
accessed.
%DEFINE LOGIN=″MYUSERID″
%DEFINE PASSWORD=″DB2WWW″
•
TRANSACTION_SCOPE : Specifies the transaction scope for SQL commands.
If the variable is not defined, the default action is ″MULTIPLE″, which means
to COMMIT only after all SQL commands in an %HTML block complete
successfully. An unsuccessful SQL command causes all previously executed
SQL commands in that block to be rolled back. Specifying ″SINGLE″ means
that a COMMIT is made after each successful SQL command in an %HTML
block.
%DEFINE TRANSACTION_SCOPE=″SINGLE″
•
SHOWSQL: Hide or display the SQL command that was executed. The
default is not to display the SQL command that was executed.
%DEFINE SHOWSQL=″YES″
•
DB_CASE: Specifies what case the SQL command should be in before
executing the command. The default is to do no conversion. Specify
″UPPER″ or ″LOWER″ to force all characters in the SQL command to upper
or lower case.
%DEFINE DB_CASE=″UPPER″
•
DTW_TABLE: The result of a SQL query is stored in this table if there are no
user-defined tables passed in.
•
SQL_CODE: This variable contains the SQL warning or error code.
Successful SQL queries result in an SQL_CODE of zero.
Query completed with SQL code $(SQL_CODE).
Commitment Control Considerations
Currently, Net.data for the AS/400 system uses commitment control so files
that are accessed for update through it must be journaled. Files that are
accessed through the SQL SELECT statement are automatically journaled for
you through the native SQL support on the AS/400 system so you do not
need to start journaling for them.
4.6.3 SYSTEM (DTW_SYSTEM) Language Environment
The SYSTEM language environment supports calls to external programs
identified in an %EXEC statement in the %FUNCTION block.
The SYSTEM language environment interprets the %EXEC statement by passing
the specified program name and parameters to the operating system for
execution using the C language system() function call. This method does not
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Unleashing AS/400 Applications on the Internet
allow Net.Data variables to be directly passed or retrieved to the executable
statements as the REXX language environment does, so the SYSTEM language
environment passes and retrieves variables in the following manner:
•
Input parameters are passed as system ″environment variables″ using the
putenv() function and can be retrieved by the executing program in a
language-specific manner.
•
Output parameters are passed back to the SYSTEM language environment
by using the language-specific equivalent of the putenv() function.
The SYSTEM language environment expects the executable to be a command or
a program. The QTMHHTP1 user profile must have the proper authority to run
the executable in addition to any resources that the executable uses.
The following simple example shows a macro named SYSM that specifies a
program as the executable, passing it one Net.Data parameter:
%define
var1 = ″OriginalValue″
%FUNCTION(DTW_SYSTEM) test(INOUT parm1) {
%EXEC{ /QSYS.LIB/PGM.LIB/TSYS0001.PGM %}
%}
%HTML(REPORT) {
<PRE>
Value of var1 before function call: $(var1)
@test(var1)
Value of var1 after function call: $(var1)
</PRE>
%}
Figure 60. System Function Macro
This is an example URL that references the macro, assuming that:
•
The macro is located in the /WWW/macro directory.
•
The HTTP server has been configured to call the Net.Data CGI-BIN program
DB2WWW.
•
The user profile that CGI-BIN programs run under (QTMHHTP1) has been
given authority to access the macro file and the file containing the REXX
program.
http://hostname/cgi-bin/db2www/WWW/macro/SYSM/report
If you chose not to create a Net.Data initialization file, the SYSTEM language
environment is enabled by default. However, if you create an initialization file
and you want to use the SYSTEM language environment, the following
configuration statement must be in the initialization file:
ENVIRONMENT(DTW_SYSTEM) /QSYS.LIB/QTCP.LIB/QTMHSYS.SRVPGM ( )
4.7 Net.Data Advanced Macro Language Examples
This section explains a few of the many functions that Net.Data has to offer. For
the complete documentation about Net.Data, please refer to the online
documentation available in several languages from the AS/400 Net.Data home
page:
http://www.as400.ibm.com/netdata
Chapter 4. Net.Data Implementation
145
4.7.1 Multiple HTML Sections
Net.Data allows you to have multiple named HTML sections in one macro. This
lets you call new HTML pages to be displayed at the browser. Using conditional
logic, your macro can branch to different pages in the same macro or to a
different macro file. To display a new page in the same macro file, you can use
the ″href″ HTML tag.
<a href=″input″>Return to previous page</a>
<a href=″end″>Go to the last page</a>
By clicking on the preceding hypertext link, the user is sent to the:
%HTML(INPUT) {....
or
%HTML(END) {....
%}
%}
section of the current macro file, depending on which link was selected.
4.7.2 Using Include Files
Include files can be served from the IFS and the QSYS file system. If you have
not created an INI file that includes the INCLUDE_PATH statement, you need to
fully qualify the path to the files so Net.Data can find them. This sample shows
three include files that get two time stamps using the REXX function ″time″,
subtract the seconds and hundredths of seconds, and show the results on the
browser.
%{***********************FUNCTION
SECTION***************%}
%FUNCTION(DTW_SQL) QUERY1 (OUT Mytable) {
select * from $(TABLE)
%report { %}
%}
%INCLUDE ″TIMERFTN.MBR″
%{********* INPUT SECTION *********************%}
%HTML (INPUT) {
<HTML>
%INCLUDE ″TIMERSTR.MBR″
...
...
...
%INCLUDE ″TIMEREND.MBR″
Figure 61. Using Include Files
The contents of the first %INCLUDE file TIMERFTN sets up the REXX command
time. It is included from the FUNCTION SECTION of the macro.
%function(dtw_rexx)
stime1(out t1) { t1 = time(′ l′ )
%}
%function(dtw_rexx) etime1(OUT t2) returns(t2){ t2 = time(′ l′ )
%}
Figure 62. Include File TIMERFTN
The contents of the second %INCLUDE file TIMERSTR starts the timer. Notice
that the first function ″@stime1″ does not have a ″returns″ parameter so the start
time is not displayed at the browser, but is stored in the variable $(t1) to print
later in the macro. We are using the Net.Data built-in function @DTW_DELSTR to
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Unleashing AS/400 Applications on the Internet
start at the first position of the string, delete the next six positions, and return
the value of the deleted string to $(d1).
@stime1(t1)
@DTW_DELSTR(t1,″ 1 ″ , ″ 6 ″ , d1)
Figure 63. INCLUDE File TIMERSTR
The contents of the third %INCLUDE file TIMEREND gets another time stamp,
and parses the time stamp to remove the hours and the colons from the time
string $(t2). We use the built in Net.Data math functions to return the elapsed
time in seconds to the browser.
<table>
<TR><TD>The end time was<TD>@etime1(t2) </TR>
@DTW_DELSTR(t2,″ 1 ″ , ″ 6 ″ , d2)
@DTW_SUBTRACT(d2,d1,d3)
<TR><TD>The start time was<TD>$(t1)</TR>
<TR><TD>The total time was<TD align=right>$(d3)</TR>
</table>
Figure 64. INCLUDE File TIMEREND
The output on the browser display looks similar to this:
The end time was 15:16:43.506000
The start time was 15:16:42.726000
The total time was
0.780000
Notice that in this example we are only subtracting the seconds and tenths of
seconds. Parsing the string can be changed to include the minutes and hours.
4.7.3 Conditional Logic
The %IF / %ELIF / %ELSE / %ENDIF block using conditional logic in your
Net.Data macros is one of the more powerful functions of the macro language.
This allows the macro writer to dynamically change the HTML in the macro that
is returned to the browser. When you think of it, imagine all the stuff you can do
with this function.
%IF ($(ROW_NUM) < $(MAX_ROWS))
<P>The table is not full yet.<BR>
%ELIF ($(ROW_NUM) == $(MAX_ROWS))
<P>The table is now full.<BR>
%ELSE
<P>The table is too small.<BR>
%ENDIF
4.7.4 Maintaining State using ″HTML″ Hidden Variables
The following example shows one way to keep track of the HTML pages and
their associated variables. This example uses REXX functions to push and pop
values from a stack and pass the values to the Net.Data macro. Using the
″nextButton″ and the ″backButton″, the field values of the form are remembered
for the user so they can change an entry on the form easily. Notice the HTML
Meta tag <META HTTP-EQUIV=″Expires″ CONTENT=″Mon, 01 Jan 1990
13:00:00 GMT″ > . This makes sure that when a user selects the ″backButton″,
the variables are not coming from the user′s cached pages.
Chapter 4. Net.Data Implementation
147
%{
Source File Name: itsoexmp.mbr
Source File Description:
This source file contains macro code that
pushes an HTML screen onto a
stack and also pops it off the stack.
%}
%{ *********
Define Section
*****************%}
%DEFINE {
FIRSTNAME = ″″
LASTNAME = ″″
MAINQ = ″″
TEMPQ = ″″
%}
%{ *************** Assign Function **********************%}
%FUNCTION(DTW_REXX) assign(IN from, OUT to) {
to = from
/* assigns the input variable to the output variable */
%}
%{ ************* Stack Push Function *********************%}
%FUNCTION(DTW_REXX) myPush(IN x, INOUT y) {
y = x′ ′ y
/* pushes ′ x′ onto stack ′ y′
*/
%}
%{ ************* Stack Pop Function **********************%}
%FUNCTION(DTW_REXX) myPop(INOUT x, INOUT y) {
parse var y x y /* pops ′ x′ off of stack ′ y′
*/
%}
%{ *********
HTML Section: main0
*****************%}
%HTML (main0) {
<html>
<head>
<META HTTP-EQUIV=″Expires″ CONTENT=″Mon, 01 Jan 1990 13:00:00 GMT″>
<TITLE>First Screen</TITLE>
</head>
<body bgcolor=″#ffffff″>
<b>First Screen</b>
@assign(mainQ,tempQ)
<p>
This is the first screen.
<p>
<form method=POST action=″main1″>
<!-- Push current panel onto my queue in case we --!>
<!-- need to find our way back --!>
@myPush(″main0″ , mainQ)
<input type=″hidden″ name=″mainQ″ value=″$(mainQ)″>
<!-- POST hidden variables -->
%INCLUDE ″itsoexm2.mbr″
<input type=″submit″ name=″nextButton″ value=″Next″>
</form>
</body>
</html>
%}
%{ ***********
HTML Section: main1
*************** %}
%HTML (main1) {
<html>
<head>
<META HTTP-EQUIV=″Expires″ CONTENT=″Mon, 01 Jan 1990 13:00:00 GMT″>
<TITLE>Second Screen</TITLE>
</head>
<body bgcolor=″#ffffff″>
<b>Second Screen</b>
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Unleashing AS/400 Applications on the Internet
@assign(mainQ,tempQ)
<p>
This is the second screen. Enter your first name.
<p>
<!-- This is the next form -->
<form method=POST action=″main2″>
<!-- Push current panel onto my queue in case --!>
<!-- we need to find our way back --!>
@myPush(″main1″ , mainQ)
<input type=″hidden″ name=″mainQ″ value=″$(mainQ)″>
Your First Name<input type=″text″ name=″firstName″
maxlength=12 size=12 value=″$(firstName)″>
<p>
<!-- This table horizontally aligns the buttons -->
<TABLE>
<TR>
<TD>
<!-- POST hidden variables -->
<input type=″hidden″ name=″lastName″ value=″$(lastName)″>
<input type=″hidden″ name=″Serial″ value=″$(Serial)″>
<input type=″submit″ name=″nextButton″ value=″Next″>
</form>
</TD>
<TD>
<!-- This is the back form -->
@myPop(prevPanel,tempQ)
<form method=POST action=″$(prevPanel)″>
<input type=″hidden″ name=″mainQ″ value=″$(tempQ)″>
<!-- POST hidden variables -->
%INCLUDE ″itsoexm2.mbr″
<input type=″submit″ name=″backButton″ value=″Back″>
</form>
</TD>
</TR>
</TABLE>
</body>
</html>
%}
%{ *************
HTML Section: main2
**************** %}
%HTML (main2) {
<html>
<head>
<META HTTP-EQUIV=″Expires″ CONTENT=″Mon, 01 Jan 1990 13:00:00 GMT″>
<TITLE>Last Screen</TITLE>
</head>
<body bgcolor=″#ffffff″>
<b>Last Screen</b>
@assign(mainQ,tempQ)
<p>
This is the last screen. Your first name is $(firstName).
<p>
<!-- This table horizontally aligns the buttons -->
<TABLE>
<TR>
<TD>
<!-- This is the back form -->
@myPop(prevPanel,tempQ)
<form method=POST action=″$(prevPanel)″>
<input type=″hidden″ name=″mainQ″ value=″$(tempQ)″>
Chapter 4. Net.Data Implementation
149
<!-- POST hidden variables -->
%INCLUDE ″itsoexm2.mbr″
<input type=″submit″ name=″backButton″ value=″Back″>
</form>
</TD>
</TR>
</TABLE>
</body>
</html>
%}
The contents of the %INCLUDE ″itsoexm2.mbr″ are shown in the following
example:
<input type=″hidden″ name=″firstName″ value=″$(firstName)″>
<input type=″hidden″ name=″lastName″ value=″$(lastName)″>
<input type=″hidden″ name=″Serial″ value=″$(Serial)″>
In this example, we are only using the ″firstName″ Hidden field. However, the
idea is to understand how to move from one HTML section to another and bring
forward or backward the field values that the user has input to the forms.
4.7.5 Net.Data Hidden Variables
Hidden variables can be used to conceal the actual name of a variable from
people who choose to view your HTML source with their Web browser.
1. Define a variable for each string you want to hide. Put the %DEFINE
statement for these variables after the %HTML block where you reference
the variables and before the %HTML block where they are to be used.
2. In the % H T M L block where the variables are referenced, use double dollar
signs instead of a single dollar sign to reference the variables (for example,
$$(name) instead of $(name)).
%HTML(INPUT) {
<FORM ...>
<P>Select fields to view:
<SELECT NAME=″Field″>
<OPTION VALUE=″$$(name)″> Name
<OPTION VALUE=″$$(addr)″> Address
....
....
....
</FORM>
%}
%DEFINE{
name=″customer.name″
addr=″customer.address″
%}
%FUNCTION(DTW_SQL) mySelect() {
SELECT $(Field) FROM customer
%}
....
....
....
When the HTML form is displayed on a Web browser, $$(name) and $$(addr) are
replaced with $(name) and $(addr) respectively, so the actual table and column
names never appear on the HTML form and there is no way to tell that the true
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Unleashing AS/400 Applications on the Internet
variable names are hidden. When the customer submits the form, the
%HTML(REPORT) block is called. When the @mySelect() statement calls the
%FUNCTION block, $(Field) is substituted in the SQL statement with
customer.name or customer.addr (depending on what the user selected) in the
SQL query.
4.7.6 Net.Data Predefined Variables
Predefined variables are supplied by Net.Data with a value set by Net.Data. You
cannot change predefined variables. A predefined variable does not have to be
explicitly defined before being referenced in a Net.Data web macro. The
following sample macro uses currently available predefined variables. Notice
that all of the variables start with ″DTW_″.
%{*********
REPORT SECTION *********************%}
%HTML (REPORT) {
<HTML>
<TITLE>Environment Variables</TITLE>
<P>
HERE ARE THE RESULTS OF ENVIRONMENT REQUESTS
<HR>
<P><TABLE BORDER>
<TR><TD>This Web macro was last modified<TD> $(DTW_MACRO_LAST_MODIFIED)
</TR>
<TR><TD>File name is<TD>
$(DTW_MACRO_FILENAME)</TR>
<TR><TD>CURRENT FILE NAME<TD>
$(DTW_CURRENT_FILENAME)</TR>
<TR><TD>Current last modified<TD>$(DTW_CURRENT_LAST_MODIFIED)</TR>
<TR><TD>Path
<TD>
$(DTW_MP_PATH)</TR>
<TR><TD>Version <TD>
$(DTW_MP_VERSION)</TR>
</TABLE>
</HTML>
%}
Figure 65. Net.Data Environment Variables Macro
Figure 66. Sample of Net.Data Environment Variables
Chapter 4. Net.Data Implementation
151
4.7.7 Net.Data Environment Variables
Net.Data environment variables allow you to reference any environment variable
that exists in the process under which Net.Data is running. To define a Net.Data
environment variable, use the actual environment variable name. You need to
define Net.Data environment variables before you use them.
%DEFINE environment_variable_name=%ENVVAR
When the variable is referenced in the Web macro, Net.Data simply gets the
environment variable′s current value. Net.Data replaces the variable reference
with the current value. For example, the following figure displays the current
values of the environment variables.
%{************** DEFINE SECTION ****************%}
%DEFINE SCRIPT_NAME=%ENVVAR
%DEFINE HTTP_USER_AGENT=%ENVVAR
%DEFINE SERVER_SOFTWARE=%ENVVAR
%{********* REPORT SECTION *********************%}
%HTML (REPORT) {
<HTML>
<TITLE>Environment Variables</TITLE>
<P>
HERE ARE THE RESULTS OF ENVIRONMENT REQUESTS
<HR>
<P><TABLE BORDER>
<TR><TD>The script name is<TD> $(SCRIPT_NAME)</TR>
<TR><TD>The requesting browser was <TD>$(HTTP_USER_AGENT)</TR>
<TR><TD>The HTTP Server Software is<TD> $(SERVER_SOFTWARE)</TR>
</table>
</HTML>
%}
Figure 67. Macro to Get Environment Variables
Figure 68. Sample Output of Environment Variables
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Unleashing AS/400 Applications on the Internet
4.7.8 Net.Data Default Report
Net.Data gives you the ability to disable the default report. The default report is
built from text characters. Net.Data can automatically build HTML tables for you
if you include the following in your macro.
%define DTW_HTML_TABLE=″YES″
Once this is defined in the macro, you can turn the value on or off by including
the following statement before the table is to be displayed with this statement.
@DTW_ASSIGN(DTW_HTML_TABLE,″NO″ )
or
@DTW_HTML_TABLE=″YES″
In some cases, you may want to display your table data using the built-in table
functions provided by Net.Data rather than displaying the table data using a
default report. These table functions produce select, radio, list, and check box
HTML objects from your Net.Data table. The easiest way not to produce a report
is to include a blank report block, %report{ %} within the function define as
illustrated in this example, which creates a select box where the
″@QUERY1(Mytable)″ causes Net.Data to execute the ″ % FUNCTION(DTW_SQL)
QUERY1...″ SQL command.
%{*********
DEFINE SECTION *********************%}
%define{
DATABASE=″*LOCAL″
TABLE=″AS0219R.BRANDS″
Mytable=%TABLE(ALL)
%}
%{***************FUNCTION SECTION***************%}
%FUNCTION(DTW_SQL) QUERY1 (OUT Mytable) {
select * from $(TABLE)
%report { %}
%}
%{********* INPUT SECTION *********************%}
%HTML (FORM1){
<HTML>
<h1>Net.Data Select Box</h1>
<FORM METHOD=″POST″ ACTION=″FORM2″>
<h3>Vehicle Selection Box</h3> <BR>
@QUERY1(Mytable)
@DTW_TB_SELECT(Mytable,″brand″ , ″ ″ , ″ 1 0 ″ , ″ N″ , ″ ″ , ″ 1 ″ )
<BR>
<INPUT TYPE=″SUBMIT″ VALUE=″Submit it″>
</FORM>
</HTML>
%}
%{********* REPORT SECTION *********************%}
%HTML (FORM2) {
<HTML>
<TITLE>Selct Box Results</TITLE>
<P>
You selected the value <B>″$(brand)″</B> from the select box
</HTML>
%}
Figure 69. Net.Data Select Box Macro
When this macro is called, it produces the following browser output. Notice that
10 [ @DTW_TB_SELECT(Mytable,″brand″,″″, ″10″,″N″ ,″″,″1″) ] rows from the
table are displayed and that the first option
Chapter 4. Net.Data Implementation
153
[ @DTW_TB_SELECT(Mytable,″brand″,″″,″10″,″N″,″″, ″1″) ] was selected as the
default selection.
Debug Tip
The HTML section FORM2 prints the environment variable that is passed by
the macro in the ″A C T I O N = ″ parameter of the FORM METHOD=″POST″. By
including the $(brand), you can see the value that was passed when the
″Submit it″ button was selected.
Figure 70. Sample Select Box
When the select button ″Submit it″ is activated by the user, it calls the macro
section HTML (FORM2) and returns this display to the browser.
4.8 Additional Tips
The following list contains distinguishing features of the OS/400 implementation
of Net.Data and some helpful hints:
•
154
Web macros can be stored in any file system. You can copy Web macros to
and from the QSYS.LIB file system to another file system by using the Copy
To Stream File (CPYTOSTMF) command and Copy From Stream File
(CPYFRMSTMF) command.
Unleashing AS/400 Applications on the Internet
Tip
You can use the Copy To Stream File (CPYTOSTMF) command to copy
your macros into the IFS. The IFS gives you the best performance when
serving your macro.
Net.Data expects the macros in the Integrated File System to be in ASCII
format. If you have the AS/400 system create the file during the copy, you
need to use the conversion table QASCII.TBL in library QSYS.LIB as shown
in the following example. By using the QOpenSys directory, you can use
long file names as shown in this example by using the .html extension.
CPYTOSTMF FROMMBR(′ qsys.lib/netdatawww.lib/ndmacros.file/tim
erend.mbr′ )
TOSTMF(′ / qopensys/timerend.html′ )
CVTDTA(*TBL)
TBL(′ / qsys.lib/qascii.tbl′ )
Figure 71. Copy to Stream File with ASCII Conversion
•
The APIs to support the Net.Data language environment interface are in the
QTMHLE service program in library QTCP. An ILE C language header file
provides the prototypes required to call the Net.Data APIs in ILE C.
Documentation about the interface can be found at
″http://www.as400.ibm.com/netdata″. To get the necessary prototypes,
include the header file as follows:
#include <dtwle.h>
The QTMHLE *SRVPGM object is included in the QTCP library.
The QSYSINC library contains header files and is optionally installable.
Make sure QSYSINC is on your system before compiling programs that use
these header files.
•
If you have problems getting a language environment to function properly,
look in the job log of the HTTP server job to see if any messages were
issued that may indicate the cause of the problem. When debugging newly
created language environments, it is best to have the minimum and
maximum number of server jobs set to two so that Net.Data requests are
funneled through one HTTP server job. This allows you to easily look at the
job log of the server to see if any messages are being logged. In addition,
every time a language environment service program is updated, you must
end the HTTP server and restart it so that Net.Data can activate the updated
service program.
•
The OS/400 implementation of Net.Data did not support the following
Net.Data features when this was published. They may be supported on
future releases:
−
%INCLUDE_URL statement. It ignores this statement if it encounters it.
−
Live connectivity using Common Gateway Interface thread management.
However, connections to databases are kept persistent across URL
invocations so that there is no performance degradation when accessing
remote databases.
−
Application programming interface support for the IBM Internet
Connection servers (ICS), NetScape servers (NS), and Microsoft′ s
Internet Information server (IIS).
Chapter 4. Net.Data Implementation
155
4.8.1 Net.Data Error Messages
Net.Data returns the following messages to alert you when a problem is found.
Return
Code
Message Text
Error Condition
-1002
″function function_name: Unable
to allocate memory.″
The server could not process a
request for storage from Net.Data.
-1001
″function function_name: Internal
code code.″
A call to an internal function
failed. This is a Net.Data internal
error. Report the problem to your
software service representative.
1000
″function function_name: Function
not found.″
The function requested on a
function call is not a supported
Net.Data built-in function.
1001
″function function_name:
Parameter parm_name contains a
null value.″
An input parameter contained a
NULL value. This may occur if
the parameter passed on the
function call has not been
previously defined in the Web
macro.
1002
″function function_name:
Parameter parm_name contains a
null string.″
An input parameter contained a
string value which consisted of
the null-terminating character.
1003
″function function_name: The
number of parameters passed is
not correct.″
The number of parameters passed
on a function call either exceeded
the maximum number allowed, or
was less than the minimum
number required by the function
being called.
1004
″function function_name:
Parameter parm_name is not a
table.″
A parameter was passed on a
function call which was required
to be a Web macro table variable,
but was instead a string variable.
1005
″function function_name:
Parameter parm_name is not a
string.″
A parameter
function call
to be a Web
variable, but
variable.
1006
″function function_name:
Parameter parm_name is not an
output parameter.″
A literal string was passed on a
function call for a parameter
which was required to be an
output parameter.
1007
″function function_name:
Parameter parm_name contains a
value which is not valid.″
One of these conditions exists:
•
•
•
•
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Unleashing AS/400 Applications on the Internet
was passed on a
which was required
macro string
was instead a table
A value was passed that
exceeded the maximum
supported value.
A value was passed that was
less than the minimum
supported value.
A value was passed that was
not one of the supported
choices.
A table row or column value
was passed that was less
than or equal to zero.
Return
Code
Message Text
Error Condition
1008
″function function_name: Value
parm_value is outside of table
bounds.″
One of these conditions exists:
•
•
1009
″function function_name: Variable
string is not in the correct
format.″
A program attempted to
modify a table′s row or
column value, but the row or
column value received was
less than 0 or greater than
the maximum number of rows
allowed in the table.
A row or column value was
received as input to a built-in
function, but the value
received was less than 0 or
greater than the current
number of rows or columns in
the table.
The syntax of the data returned
by a system or Perl program is
not correct. One of these
conditions exists:
•
•
•
•
An equal sign was not found.
A beginning quote was not
found.
An ending quote was not
found.
A space separator between
values was not found.
1010
″function function_name: Not all
requested data could be
returned.″
A table was specified as an output
parameter, but the number of
rows of data returned by the
language environment was
greater than the maximum
number of rows allowed for the
table. Data was written to the
table until it was full, and the
remainder of the data was
discarded.
2000
″function function_name: The
requested file filename was not
found.″
A flat file interface built-in
function could not find the
specified file in the directories it
was allowed to search.
2001
″function function_name: The
requested file filename could not
be opened in the specified mode.″
A flat file interface built-in
function could not open the
specified file because it was in
use by this or another process,
and could not be shared in the
specified mode.
2002
″function function_name: The
requested file filename was not
opened.″
A flat file interface built-in
function could not close the
specified file because it was not
opened by this macro invocation.
Chapter 4. Net.Data Implementation
157
Return
Code
Message Text
Error Condition
2003
″function function_name:
Attempted to read a row of data
that exceeded the maximum
supported number of bytes.″
A flat file interface built-in
function could not read a row of
data into a table variable because
the number of bytes in the row
exceeded the maximum supported
number of bytes.
2004
″function function_name: A path
specified in FFI_PATH exceeded
the maximum supported number
of bytes.″
A flat file interface built-in
function was attempting to find a
file, but encountered a path in the
FFI_PATH configuration file
variable that was longer than the
maximum supported number of
bytes.
2005
″function function_name: System
call error text″
A call to a system function failed.
This is an internal error reported
to Net.Data that may require user
interaction or it may be a
temporary system error that is
not appropriate for Net.Data to
handle. If this problem persists,
report the problem to your
software service representative.
2006
″function function_name: The
requested file name could not be
accessed in the specified mode.″
A flat file interface built-in
function could not access the
specified file because it was in
use by this or another process
and could not be shared in the
specified mode.
3001
″function function_name: Registry
registry_name already exists.″
A Web registry built-in function
could not create a Web registry
because the specified registry
already existed.
3002
″function function_name: Registry
registry_name is in use by
another process or does not
exist.″
A Web registry built-in function
could not delete the specified
registry:
•
•
158
The registry was in use by
another process.
The registry could not be
found.
3003
″function function_name: Registry
entry registry_entry already
exists.″
A Web registry built-in function
could not add an entry to the
specified registry because the
specified entry already existed.
3004
″function function_name: Registry
entry registry_entry cannot be
found.″
A Web registry built-in function
could not remove or retrieve an
entry from the specified registry
because the specified entry did
not exist.
3005
″function function_name: Registry
registry_name cannot be found.″
A Web registry built-in function
could not use the specified
registry because it could not be
found.
Unleashing AS/400 Applications on the Internet
Return
Code
Message Text
Error Condition
3006
″function function_name: Path in
registry registry_name does not
exist.″
A Web registry built-in function
could not create the specified
registry because a path in the
registry name did not exist.
3007
″function function_name: You are
not authorized to perform the
requested registry operation.″
A Web registry built-in function
could not complete the specified
operation because the requestor
did not have the proper authority
to the specified registry.
3008
″function function_name: Registry
registry_name failed to create.″
A Web registry built-in function
could not create the specified
registry for unknown reasons.
4000
″function function_name:
Parameter parm_name is not a
whole number or is too large.″
One of these conditions exists:
•
•
•
4001
″function function_name:
Parameter parm_name is not a
valid number.″
An input parameter contained
a value that was not a whole
number.
An input parameter contained
a value that was greater than
the supported maximum of
999,999,999.
An output cannot be
expressed as a whole
number.
One of these conditions exists:
•
•
An input parameter contained
a value that was not a valid
format for a number.
An input parameter contained
a value that specified an
exponent outside the
supported range of
-999 999 999 to +999 999 999.
4002
″function function_name:
Arithmetic overflow or underflow.″
The result of an arithmetic
operation had an exponent that
was outside the supported range
of -999 999 999 to +999 999 999.
5000
″function function_name: EXEC
statement is empty.″
The string specified in the %EXEC
statement of a function block
contained only space characters.
6000
″function function_name: EXEC
was not specified in the function
block.″
A %EXEC statement was not
specified in the function block for
the function being called.
4.9 Getting Net.Data Up and Running
To enable Net.Data, you must do the following steps:
1. Copy the Net.Data program object to your CGI-BIN library. (This is not
absolutely necessary; see the following Security Alert message box.)
2. Configure the HTTP server by adding specific directives to the configuration
file.
3. Create a Net.Data initialization (INI) file (optional).
Chapter 4. Net.Data Implementation
159
4. Grant authority to the QTMHHTP1 user profile to objects that are accessed
by the Net.Data program.
Let′s take an in-depth look at each of the preceding steps to enable Net.Data on
the AS/400 system.
1. Copy the Net.Data Program Object to a CGI-BIN library.
Systems Management Issue
If you move the DB2WWW program out of the QTCP library, it is not
updated automatically by the PTF process or when you install a new
release. You need to have a good system management process in place
to update the DB2WWW program when needed. (You can use the
following untested suggestions as an alternative to moving DB2WWW
program out of QTCP library.)
Security Alert
If you choose to leave the DB2WWW program in the QTCP library, you
need to configure an EXEC statement to the QTCP library. This can open
a security hole that allows any browser to run any program in the library
QTCP if a MAP or PASS statement to the QTCP library is in the HTTP
configuration file. One way to avoid this is shown in ″Alternative Setup to
Leave DB2WWW in QTCP″ on page 161.
The Net.Data program (DB2WWW) should be copied to a CGI-BIN library.
The DB2WWW program is located in the QTCP library. You can copy the
program object using the Create Duplicate Object (CRTDUPOBJ) command.
The DB2WWW program object′s authority for *PUBLIC users is set to
*EXCLUDE. Change the DB2WWW program object in the CGI-BIN directory
so that the user profile that CGI programs run under (QTMHHTP1) has
access to the program object. You can do this by changing the program
object′s authority for *PUBLIC users to *USE, or by specifically giving the
QTMHHTP1 user profile *USE access to the DB2WWW program object.
2. Add Net.Data Directives to the HTTP configuration file:
Use option 1 (Add) or option 13 (Insert) of the Work with HTTP Configuration
(WRKHTTPCFG) command to do the following steps:
a. Ensure that the Enable GET and Enable POST directives are in the
configuration file.
b. Add Map and Exec directives for Net.Data.
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Unleashing AS/400 Applications on the Internet
Alternative Setup to Leave DB2WWW in QTCP
One solution is to temporarily remap the incoming URL to a bogus
one, Fail /QSYS.LIB/QTCP.LIB/*, and remap the temporary bogus URL
back to /QSYS.LIB/QTCP.LIB/*. This looks similar to the following:
Map
Fail
Map
Exec
/QSYS.LIB/QTCP.LIB/DB2WWW.PGM/* /DB2WWWBOGUS/*
/QSYS.LIB/QTCP.LIB/*
/DB2WWWBOGUS/* /QSYS.LIB/QTCP.LIB/DB2WWW.PGM/*
/QSYS.LIB/QTCP.LIB/*
Examples:
•
For http://QSYS.LIB/QTCP.LIB/DB2WWW.PGM/..., this is mapped
to /DB2WWWBOGUS. The Fail does not happen. The next Map
fixes the bogus URL. And the final Exec allows the
DB2WWW.PGM to execute.
•
For http://QSYS.LIB/QTCP.LIB/FTP.PGM/..., this does not do the
first Map and subsequently fails with the next directive.
•
For http://qsys.lib/qtcp.lib/ftp.pgm/..., this does not Map, Fail, or
Exec due to any of the preceding directives because they are
case sensitive. So, it falls through all of the preceding directives
and eventually fails after all of the directives had been exhausted.
Carefully planning the HTTP server configuration file is important to
maintain the integrity of the servers files and programs from harm.
If they are not already there, add the Enable GET 1 and Enable POST 2
directives to the section of the configuration file where you enable methods.
With the directives in the file, your display is similar to the display shown in
the following figure:
Work with HTTP Configuration
System:
Type options, press Enter.
1=Add
2=Change
3=Copy
Opt
Sequence
Number
4=Remove
5=Display
SYSNAM01
13=Insert
Entry
00010
00020
00030
00040
00050
00060
00070
00080
00090
00100
00110
00120
# * * * * * * * * * * * * * * * * * * * * * * * * * * #
# HTTP CONFIGURATION FOR NET.DATA TESTING
#
#
#
HostName sysnam01.location.company.com
Port 80
#----------------------------------------------------# Methods Enabled
#
Enable GET 1
Enable POST 2
#
#----------------------------------------------------More...
F3=Exit
F5=Refresh
F6=Print List
F12=Cancel
F17=Top
F18=Bottom
F19=Edit Sequence
Figure 72. Get and Post Statements
Chapter 4. Net.Data Implementation
161
Add the Map and Exec statements shown in Figure 73 on page 162. This
display shows the directives after they have been added.
Work with HTTP Configuration
System:
Type options, press Enter.
1=Add
2=Change
3=Copy
Opt
Sequence
Number
00130
00140
00150
001603
001703
00180
00190
002004
00210
00220
4=Remove
5=Display
SYSNAM01
13=Insert
Entry
#----------------------------------------------------#
Mapping/Pass Rules + Executables
#
Map /cgi-bin/db2www/* /QSYS.LIB/CGI.LIB/DB2WWW.PGM/*
Map /CGI-BIN/DB2WWW/* /QSYS.LIB/CGI.LIB/DB2WWW.PGM/*
#
#
Exec /QSYS.LIB/CGI.LIB/*
Pass /WWW/html/*
#-----------------------------------------------------
F3=Exit
F5=Refresh
F19=Edit Sequence
F6=Print List
F12=Cancel
F17=Top
More...
F18=Bottom
Figure 73. Map and Exec Statements
The Map directives 3 map entries in the form ″/cgi-bin/db2www/*″ to the
library where the Net.Data program resides on your system. (The asterisk
(*) at the end of the string refers to anything that follows the string.) Both
upper-case and lower-case map statements are included because the
directives are case sensitive. In this example, both Map statements map to
the same location.
The Exec directive 4 enables the HTTP server to execute any CGI
programs in the CGI library. Specify the library where the program resides
(not the program itself) on the directive. To prevent other *PGM objects in
the CGI library from being executed, exclude *PUBLIC and QTMHHTP1 from
object access.
You must restart the HTTP server for changes to the configuration file to take
effect.
3. Create the Net.Data initialization file:
The creation of the Net.Data initialization file is optional. If an initialization
file is not created, Net.Data runs as if an initialization file with only the
default language environment statements in the file had been configured. All
macro, include, and executable references need to be fully qualified.
If an initialization file is created and updated, you do not need to end or
restart the HTTP server for the changes to take effect. Net.Data reads the
initialization file once during the initial invocation by an HTTP server job.
The configuration data is saved so that on subsequent Net.Data invocations,
Net.Data does not have to read the initialization file. However, if a change is
made to the initialization file, Net.Data detects the change to the initialization
file and reads the initialization file again.
Use the Create Source Physical File (CRTSRCPF) command to create the
initialization (INI) file. Since the text of configuration statements must all be
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Unleashing AS/400 Applications on the Internet
on one line, it is a good idea to create the initialization file with a record
length of 240. The file must be created in the library where the DB2WWW
program object resides. The file name must be ″INI.″ The member name
must be ″DB2WWW″. Use the Source Entry Utility (SEU) to add configuration
statements to the file. A sample initialization file is shown in the following
figure. The text of the environment statements must all be on one line.
These statements are shown on several lines in this example for readability.
MACRO_PATH
INCLUDE_PATH
EXEC_PATH
/WWW/MACROS;/QSYS.LIB/WWWMACROS.LIB/MACROS.FILE
/WWW/INCLUDES
/QSYS.LIB;/QSYS.LIB/WWWPGMS.LIB
ENVIRONMENT(DTW_REXX) /QSYS.LIB//QTCP.LIB/QTMHREXX.SRVPGM ( )
ENVIRONMENT(DTW_SQL) /QSYS.LIB/QTCP.LIB/QTMHSQL.SRVPGM (IN DATABASE,
LOGIN, PASSWORD, TRANSACTION_SCOPE, SHOWSQL, DB_CASE,
OUT DTWTABLE, SQL_CODE)
ENVIRONMENT(DTW_SYSTEM) /QSYS.LIB/QTCP.LIB/QTMHSYS.SRVPGM ( )
Figure 74. Contents of Net.Data Initialization (INI) File
Net.Data on the AS/400 system recognizes three special path statements. It
uses these statements to determine where to look for files to process:
•
MACRO_PATH
•
EXEC_PATH
•
INCLUDE_PATH
These path statements identify a set of directories that are searched by the
Web macro processor for Web macros, include files, and executable files.
Each directory specified is delimited by a semi-colon (″;″). Forward slashes
(″/″) and backward slashes (″\ ″) are treated the same. The multiple-path
capability of the MACRO_PATH, EXEC_PATH, INCLUDE_PATH, and
HTML_PATH statements enable different products using Net.Data to be
isolated to their own directories.
The format of the MACRO_PATH statement is:
MACRO_PATH /pathname[;pathname ...]
The MACRO_PATH statement identifies one or more directories to search in
the order in which they are specified for a Net.Data macro file. Net.Data
uses the PATH_INFO environment variable when resolving to a Web macro.
For example, if the following URL was used to send a Net.Data request:
http://hostname/cgi-bin/db2www/WWW/macro/SQLM/report
the portion of the URL that Net.Data considers to be the Web macro name is
″/WWW/macro/SQLM″. Net.Data appends the path to the paths in the
MACRO_PATH configuration statement from left to right until the Web macro
is found. If the Web macro is not found, Net.Data assumes that
″/WWW/macro/SQLM″ references the Web macro.
The path statements for the MACRO_PATH configuration statement can be
integrated file system directories (IFS) and QSYS.LIB directories. For
example, if macros are in the IFS directory /WWW/MACRO and in the
QSYS.LIB directory of /QSYS.LIB/WWW.LIB/MACRO.FILE, the MACRO_PATH
statement looks similar to this:
MACRO_PATH /WWW/MACRO;/QSYS.LIB/WWW.LIB/MACRO.FILE
Chapter 4. Net.Data Implementation
163
The format of the EXEC_PATH statement is:
EXEC_PATH pathname[;pathname ...]
The EXEC_PATH statement identifies one or more directories to search in the
order in which they are specified to find an external program invoked using
the %EXEC statement. If the program is found, the external program name
is appended to the path specification resulting in a qualified file name which
is passed to the language environment for execution.
For example, if programs are stored in a library called WWWPGMS, the
EXEC_PATH statement looks similar to this:
EXEC_PATH /QSYS.LIB/WWWPGMS.LIB
The format of the INCLUDE_PATH statement is:
INCLUDE_PATH pathname[;pathname ...]
The INCLUDE_PATH identifies one or more directories that are searched in
the order in which they are specified to find a file specified on the
%INCLUDE statement in a Net.Data macro. When found, the include file
name is appended to the path specification to produce the qualified include
file name. You can specify IFS and QSYS.LIB directories.
The ENVIRONMENT statement is used to configure a language environment.
Net.Data′s language environment allows you to directly run REXX programs,
query the database, and access high level programs on the AS/400 system.
Further setup considerations for the language environments are explained in
Section 4.6, “Language Environments” on page 139. The syntax of the
language environment configuration statement is:
ENVIRONMENT(type) srvpgm-name ([usage argument, ...])
A language environment configuration statement consists of the following
data:
•
A type name for associating it with the type field of a %FUNCTION block.
•
A service program name.
•
A list of optional arguments that are passed to the service program′ s
entry points.
4. Grant QTMHHTP1 user profile authority to objects.
The user profile that CGI programs run under (QTMHHTP1) must have the proper
access to any objects that are referenced in a Web macro and to the macro that
a URL references. One way to grant authority to the QTMHHTP1 user profile is
to use the Change Authority (CHGAUT) command, which allows you to grant
authority to objects that reside in the QSYS.LIB file system in addition to objects
residing in the integrated file system that are not in the QSYS.LIB file system.
For example, if Web macro files reside in the /WWW/macro directory and in the
/QSYS.LIB/WWW.LIB/MACRO.FILE directory, the following commands need to be
issued:
CHGAUT OBJ(′ / WWW′ ) USER(QTMHHTP1) DTAAUT(*RX)
CHGAUT OBJ(′ / WWW/macro′ ) USER(QTMHHTP1) DTAAUT(*RX)
CHGAUT OBJ(′ / WWW/macro/*′ ) USER(QTMHHTP1) DTAAUT(*RX)
CHGAUT OBJ(′ / QSYS.LIB/WWW.LIB′ ) USER(QTMHHTP1) DTAAUT(*RX)
CHGAUT OBJ(′ / QSYS.LIB/WWW.LIB/MACRO.FILE′ ) USER(QTMHHTP1) DTAAUT(*RX)
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Unleashing AS/400 Applications on the Internet
4.9.1 Example URL Calling Net.Data Macro
This is how the AS/400 HTTP server configuration and the Net.Data configuration
work together to build the path to the Macro and which HTML section the Macro
will execute.
Figure 75. Sample Net.Data URL
Chapter 4. Net.Data Implementation
165
4.10 Migrating from DB2 WWW Connection to Net.Data
If you are using DB2 WWW Version 1 and want to migrate to Net.Data (DB2WWW
Version 2), read Section 4.9, “Getting Net.Data Up and Running” on page 159.
After reading the section, you may need to create a Net.Data initialization file.
As explained in the section Getting Net.Data Up and Running , you need to create
an initialization file for URLs that reference Web macros that are not fully
qualified in the Web macro. If you need to create a configuration file, you need
to add the SQL language environment statement in the configuration file SQL
(DTW_SQL or SQL) Language Environment . For information on the syntax of the
SQL language environment statement, see Section 4.6.2, “SQL (DTW_SQL or
SQL) Language Environment” on page 141.
With DB2 WWW Connection Version 1, you needed an initialization file in every
library in which macro files resided. This is no longer true with Net.Data. If you
choose to create a Net.Data initialization file and you use the MACRO_PATH
configuration statement in your DB2 WWW Version 1 initialization files, you need
to combine the path statements into one path statement and insert the combined
path statement in the initialization file in the library where the DB2WWW
program object resides. Once Net.Data is serving Web macros, you should
delete all the DB2 WWW Version 1 initialization files that are not being used.
4.11 Debug HTTP Server Setup for Net.Data
For the following problems, assume that the Net.Data CGI-BIN program object,
DB2WWW, has been moved to a library named WWWCGI where your CGI-BIN
programs reside.
SYMPTOM
Error 500 (text of message follows)
Bad script request -- ′ / QSYS.LIB/WWWCGI.LIB/DB2WWW.PGM/
QSYS.LIB′ not executable
CAUSE: Incorrect Exec rule.
Exec /QSYS.LIB/WWWCGI.LIB/DB2WWW.PGM/*
Exec /qsys.lib/wwwcgi.lib/db2www.pgm/*
SOLUTION: Specify an Exec rule that only supplies the path to the DB2WWW
program. For example:
Exec /QSYS.LIB/WWWCGI.LIB/*
Exec /qsys.lib/wwwcgi.lib/*
SYMPTOM
Error 404 (Text of message follows)
Not found - file doesn′t exist or is read protected [ even tried
multi ]
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Unleashing AS/400 Applications on the Internet
CAUSE: There is an Exec rule missing.
SOLUTION: Specify an Exec rule that supplies the path to the DB2WWW program
in both upper and lower case. For example:
Exec /QSYS.LIB/WWWCGI.LIB/*
Exec /qsys.lib/wwwcgi.lib/*
SYMPTOM
Error 403 (Text of message follows)
Forbidden - by rule
CAUSE: A Map or Exec rule is missing or incorrect.
SOLUTION: Specify a Map and Exec rule for the DB2WWW program in both
upper and lower case. For example:
Map /cgi-bin/db2www/* /QSYS.LIB/WWWCGI.LIB/DB2WWW.PGM/*
Map /CGI-BIN/DB2WWW/* /QSYS.LIB/WWWCGI.LIB/DB2WWW.PGM/*
Exec /QSYS.LIB/WWWCGI.LIB/*
SYMPTOM
Configuration Statements Correct but Net.Data Not Working
This problem occurs when all configurations are present and correct but
Net.Data is still not serving data or documents correctly (or at all). There are
several possible causes and solutions:
CAUSE
SOLUTION
Map, Exec, or Pass rules are not in the correct order.
When a URL is evaluated against a Map, Exec, or Pass rule, it is
acted on based on the first matching rule. Therefore, you must be
careful to ensure that the statement to be evaluated is not remapped
or altered prior to reaching the desired rule. Also, make sure that
you do not have a ″Pass /*″ in the configuration file.
User profile QTMHHTP1 does not have proper authority to access Web macros.
All CGI-BIN programs run under the user profile QTMHHTP1. The
QTMHHTP1 user profile must be granted authority to all objects that
Net.Data accesses while processing a Web macro.
Path statements in the Net.Data initialization file are not correct.
Net.Data uses the path statements in the initialization file (if there is
one) to resolve to any Web macro or executable references in the
Web macro that is being processed. If the object references are not
fully qualified and the path statements in the initialization file are not
correct, Net.Data indicates that the object being referenced is not
found. Therefore, you must make sure that either the object
references are fully qualified or the Net.Data initialization file has the
proper path statements.
Chapter 4. Net.Data Implementation
167
4.12 Service and Support
Net.Data is not a separate product in OS/400. The Net.Data function has been
integrated directly into OS/400′s TCP/IP software; see IBM TCP/IP Connectivity
Utilities/400 Version 3 Release 7 (Program 5716-TC1). V3R2 users can obtain the
Net.Data function by requesting the correct PTFs as shown in the following list:
To receive IBM AS/400 service and support for a Net.Data issue, you should treat
it the same as you do any other IBM OS/400 software issue and report it to IBM
through your normal procedures.
PTFs and known problems can be found at the Net.Data page:
http://www.as400.ibm.com/netdata
For the examples in this chapter to work, you need to have the following PTFs
applied to your system.
V3R7M0
V3R2M0
Net.Data
SF38425 1
SF38428 1 2
Net.Data (Include File)
SF34468
SF36743
Note:
1. You should always load the latest PTFs.
2. It overlays DB2 WWW Connection if you have not already applied PTF SF36975.
Note that even if you do not load this PTF, any HTTP server PTF you load after
the release date of PTF SF36975 results in Net.Data being enabled on your
system.
The following table lists PTFs that impact Net.Data. Note that the PTFs may have
been superseded by other PTFs.
V3R7M0
V3R2M0
HTTP Server
SF37633 1
N/A
C / C + + Runtime
SF35079 1
N/A
Database
SF35074 1
SF38554 1
Database (ACL)
SF38031 1
SF38030 1
REXX
SF34680
SF34679
NLS
N/A
MF14090 2
Other
N/A
N/A
Note:
1. Must be loaded for Net.Data to function properly.
2. Must be loaded to enable DBCS support.
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Unleashing AS/400 Applications on the Internet
Chapter 5. HTML Gateway Implementation
Web browsers can directly access many Internet Information Services, but the
presentation of some complex data formats and commercial applications often
need some help. For instance, application programs written using CGI-bin are
needed in addition to the basic Web server to read relational databases,
dynamically build Web pages containing the database records, and transmit
them to the Web browser. We have seen the use of such implementations for
the AS/400 system using CGI-bin and Net.Data in the previous two chapters.
HTML gateways allow Web clients to access your database, middleware, or
applications through the Web server without you having to make any changes to
the existing applications, or even to write any additional code.
Most Web servers today require that you write scripts or programs to create
interactive forms and applications for the Internet. For most software providers,
this can mean learning new tools and procedures if they want to this enhanced
Internet functionality. This is not true for existing AS/400 customers. By using
an HTML gateway function, your current development tools work for creating
Internet or Intranet applications. Once your AS/400 applications are created, you
can start using the Internet′s worldwide reach to open new marketing
opportunities. Existing AS/400 applications can run over the Web without
modifying any code. There is no conversion program to run. Just install and
configure the gateway and the applications on your AS/400 system are ready to
go!
Why should a company use an HTML gateway?
Take the case of an typical company, as shown in Figure 76 on page 170, the
existing business situation can fully utilize existing applications and data on the
Web with no coding required. The HTML gateway provides a rapid way of taking
advantage of the Internet.
This chapter describes the two HTML gateways that are available for the AS/400
system, how to utilize them, and describes some of the differences between
them. The final sections of this chapter provide pointers to additional sources of
information on HTML gateways and discuss some of the pros and cons of
application enablement versus the use of CGI-bin and Net.Data programming.
 Copyright IBM Corp. 1997
169
Figure 76. A Typical Company Showing the HTML Gateway Link to the Internet
5.1 What is an HTML Gateway?
An HTML gateway provides automatic translation between 5250 data streams
and HTML. The 5250 data stream that is normally sent to end users′ displays is
intercepted. The display layout is evaluated including variable data fields and
static text. By performing efficient translation between 5250 data and HTML, the
user interface (terminal) to your AS/400 application becomes
platform-independent.
In addition, the application can be made globally accessible with a more visually
appealing user interface. It means that your AS/400 application can have a
much improved user interface, using the Web browser as an alternative to the
5250 interface. No AS/400-specific software is needed on the users′ end system.
Currently, two HTML gateways exist for the AS/400 system, one provided by IBM
and the other by I/NET. IBM′s product is called Workstation Gateway and is
provided as part of Internet Connection for AS/400, which is provided at no cost
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Unleashing AS/400 Applications on the Internet
with versions V3R2 and V3R7 of OS/400. I/NET′s product is called Webulator/400
and operates in conjunction with I/NET′s AS/400 Web server products, either
Web Server/400 or Commerce Server/400. I/NET′s products are available at a
cost but can be used with earlier versions of OS/400.
So how is it done?
AS/400 applications are inherently display-oriented. That means, each
application creates a series of displays for use in its application. These displays
are normally sent out in a 5250 data stream to the workstation or emulator,
which shows the text. The HTML gateway intercepts this 5250 data stream and
converts it to HTML, a language the Web understands. Any Web browser used
for accessing the World Wide Web can work with the application.
Figure 77. Workstation Gateway
An HTML gateway means your business does not need to rely on one specific
client platform. Any PC that has a Web browser installed can run AS/400
applications. There is no additional connection configuration. Just point your
Web browser to the AS/400 system and you are in business!
If your company writes AS/400 applications, using an HTML gateway means a
wealth of new applications on the Internet. You do not need to retrain your
programmers. They can continue using their existing development tools (RPG,
COBOL, C, and DDS). Also, with AS/400 HTML Gateway, your programmers can
enhance and jazz up your applications by adding graphics and other HTML tags.
Chapter 5. HTML Gateway Implementation
171
It requires only a small change to the DDS specifications and does not affect
your workstation users.
5.2 Using the HTML Gateway in Application Development
Having decided upon the use of an HTML gateway, there are various routes you
might take. Figure 78 shows the implementation route that you might adopt
depending on your application requirement. You must consider whether you are
proposing to use your applications on the Internet or the Intranet and,
consequently, what login type and security is required. In addition, you must
examine the level to which you want to “enhance” your applications. You might
also want to restrict the number of displays that are shown, or even develop
completely new applications for the web.
Figure 78. 5250-HTML Gateway Implementation Route
Notes:
1. At present it is only possible to implement a 5250-HTML gateway secure
transaction by running I/NET′s Webulator/400 and Commerce Server/400
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Unleashing AS/400 Applications on the Internet
products. To use this functionality, you should consult the I/NET
documentation available with that product.
2. If the user has an AS/400 sign-on display, the USERID and PASSWORD are
transmitted as plain text over the Web. This means that unauthorized users
might gain access to the AS/400 system. A preferred method is to provide a
Logon Exit program whereby the USERID and PASSWORD are not
transmitted over the Web. Alternatively, Webulator/400 provides the ability
to encode the USERID and PASSWORD before sending the data to the
server.
3. The existing application can be fully utilized depending on the user profile.
There may be several hundreds of displays, all of which are available.
Absolutely no code changes are required.
4. The same as the preceding item but the displays are enhanced by using the
new DDS HTML keyword. This requires code changes and recompilation of
the DDS files.
5. Using the existing application but providing a limited set of purpose-written
HTML displays using the new DDS keyword. For example, three new
screens might be provided for order status, order input, and account enquiry.
Such displays access the existing routines and data. This implementation
provides for the case where you want to provide limited access to your
existing applications and data.
6. You might choose to design a completely new application, tailored
exclusively for use over the Internet. Your application and display design
can be created without having to consider ″green screen″ output.
Further details of the methods of application enhancement are discussed in
Section 5.4, “Application Development with Workstation Gateway” on page 181
and Section 5.7, “Application Development with Webulator/400” on page 204
5.3 IBM Workstation Gateway (WSG)
Workstation Gateway is the 5250-HTML gateway from IBM available on the
AS/400. You can use your current applications or even develop new Web
applications using such tools as RPG, COBOL, DDS, ILE C, etc.
5.3.1 Getting Started
This section explores the WSG support available on the AS/400. It describes in
details how to configure and use the WSG to build your Web applications.
5.3.1.1 Starting the Workstation Gateway Server
Important Note
Some of the examples discussed here are taken from the redbook Cool Title
About the AS/400 and Internet , SG24-4815-01.. You might first want to install
the ITSO Company demonstration and other AS/400 Web-based applications
from the CD-ROM that came with this redbook. Please see Appendix A,
″Installing the ITSO Company Demo″ in the Cool Title About the AS/400 and
Internet for instructions on how to get your AS/400 system up and running
right away.
Chapter 5. HTML Gateway Implementation
173
Important Note
Install the following PTFs for licensed program 5763-TC1 before using the
Workstation Gateway:
•
•
For V3R2, apply SF37790
For V3R7, apply SF37791
Check the Web site listed in Section 5.11.1.1, “Support Pages on the Internet”
on page 216 for the latest PTF information.
Do not confuse the Workstation Gateway with the HTTP Web server. The HTTP
Web server allows the AS/400 system to act as a Web server on the Internet.
The Workstation Gateway converts your 5250 data stream to HTML. Both
servers can be started and function independently from each other.
The Workstation Gateway is a TCP/IP application that services requests from
HTTP clients. After the initial request is received from a client, a free port is
arbitrarily allocated to the client and that client is considered “active”. All future
connections requests for that client occur over the same port number.
The client remains active until the session is signed off or an inactivity timeout
limit is reached.
Note
The Workstation Gateway maintains the illusion that the browser is logically
(or permanently) connected to the AS/400 system, even though every
transaction between the browser and the AS/400 server is a once-only
connection. The Workstation Gateway server maintains the virtual terminal
API connection indefinitely or until the browser logs off or the inactivity
timeout value is exceeded.
The Workstation Gateway server is started through the STRTCPSVR
SERVER(*WSG) command and ended with the ENDTCPSVR SERVER(*WSG)
command.
Note: Be sure to check the Workstation Gateway attribute to see if the Display
Signon (DSPSGN) parameter is set to *YES or else you do not get the Signon
display. You can use CHGWSGA command and prompt to check it.
After you start or end the Workstation Gateway, you can use WRKACTJOB
SBS(QSYSWRK) command to check the QSYSWRK subsystem to see whether
the QTWSGnnnn jobs are there or not (′nnnnn′ is a unique numeric string that is
derived from the timestamp). Alternatively, it is started through the AUTOSTART
option of the STRTCP command.
The format of a link in an HTML document is called a Universal Resource
Locator (URL). For HTTP, the URL identifies the protocol that the browser should
use when contacting the server (for example, HTTP, FTP, WAIS, Gopher, and so
on), the location of the server, and of the requested object. HTTP has the
following form:
http://hostname:port/path
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Unleashing AS/400 Applications on the Internet
The port numbers for most TCP/IP applications such as FTP, Telnet, or WWW are
predefined or you might say “well-known” numbers, which means everyone
knows them and uses the same port numbers.
The Workstation Gateway does not have such a well-known port number such as
the HTTP server has. Therefore, the port number used by the AS/400
Workstation Gateway is found by querying the local TCP/IP configuration
services database. To establish a Workstation Gateway session, you must
connect to it by using the form:
http://hostname:port/WSG
where port is the configured port number for that Workstation Gateway. The
default is a TCP port of 5061.
Note: It appears that this port number cannot be changed.
5.3.1.2 Further Workstation Gateway Configuration
This section discusses some specific configuration and software requirements
for Workstation Gateway. For more complete documentation of the detailed
installation or configuration of the product, you should refer to the following
publications:
1. TCP/IP Configuration and Reference, Version 3, SC41-3420-04
2. Cool Title About the AS/400 and the Internet , SG24-4815-01
5.3.1.3 Configure TCP/IP WSG (CFGTCPWSG) Main Menu
The easiest way to configure the Workstation Gateway is to use the menus. The
following examples show the sequence of the configuration commands.
The following display appears if the CFGTCPWSG command is entered on the
command line, or if CFGTCPAPP option 15 is selected.
Configure TCP/IP Workstation Gateway
System:
SYSNM011
Select one of the following:
1. Change workstation gateway attributes
Related options:
10. Configure HTTP
11. Work with auto configure virtual devices
12. Work with limit security officer device access
Selection or command
===>
F3=Exit
F4=Prompt
F9=Retrieve
F12=Cancel
Figure 79. CFGTCPWSG Display
•
•
•
•
Option
Option
Option
Option
1 - Prompts the CHGWSGA CL command.
10 - Calls the CFGTCPHTTP CL command.
11 - Calls WRKSYSVAL SYSVAL(QAUTOVRT)
12 - Calls WRKSYSVAL SYSVAL(QLMTSECOFR)
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175
5.3.1.4 Change Workstation Gateway Attributes (CHGWSGA)
Command Prompt
The following display appears if the CHGWSGA command is prompted from the
command line or if CFGTCPWSG option 1 is selected.
The values shown are the current values as determined by the Prompt Override
Program for CHGWSGA.
Change Workstation Gateway Attributes (CHGWSGA)
System:
SYSNM011
Type choices, press Enter.
Autostart . . . . . . . . . . .
*NO
*NO, *YES, *SAME
Number of clients per server job
20
1-50, *SAME, *DFT
Inactivity timeout . . . . . . .
10
0-60 minutes, *SAME, *DFT
Data request timeout . . . . . .
10
1-1200 seconds, *SAME, *DFT
Display sign on panel . . . . .
*YES
*SAME, *NO, *YES
Access logging . . . . . . . . .
*NO
*SAME, *NO, *YES
Top banner URL . . . . . . . . .
*NONE___________________________________
___________________________________________________________________________
Bottom banner URL . . . . . . .
*NONE___________________________________
___________________________________________________________________________
___________________________________________________________________________
__________________________________________________________
F3=Exit
F4=Prompt
F24=More keys
F5=Refresh
F12=Cancel
F13=How to use this display
Figure 80. Change Workstation Gateway Attributes Display
Since many clients can be expected to use the Workstation Gateway Server, it is
important to try to always have free servers waiting for new connect requests.
To stay ahead of potential load demands, jobs are “pre-started” to avoid
SBMJOB latency when a new server job is close to being needed.
When we say “pre-started”, we mean that we submit a new child server with the
SBMJOB when the number of available jobs (remember we are multiplexing
connections within a single batch server job) goes below threshold limits. The
threshold limit is determined based upon the value selected for the configured
number of clients.
Number of Workstation Gateway Server Clients Per Server Example
Assume that you configured five client sessions per server job. The
workstation gateway server ensures that four jobs are available for work.
The four jobs allow 20 clients to use the workstation gateway server
concurrently with this configuration (five client sessions times four server
jobs totals 20 client sessions). The server always ensures enough jobs are
running to provide at least 20 client sessions.
There are two types of timeouts for the Workstation Gateway Server:
1. Inactivity timeout (INACTTIMO) - default 10 minutes:
Specifies the number of minutes the system allows a Workstation Gateway
session to remain inactive before it is ended. When a Workstation Gateway
session is inactive longer than the specified length of time, it is ended.
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Unleashing AS/400 Applications on the Internet
Note: It may take the system an additional 1 to 120 seconds to end the
inactive session.
If a Workstation Gateway session is ended by the system, you see a
message on the Web Browser display ″Session in use - perhaps your
session expired?″ when you try to continue the operation.
2. Data request timeout (DTARQSTIMO) - default 10 seconds:
Specifies the number of seconds from the time a browser connects until the
client′s request data is received by the Workstation Gateway.
Note
What happens when the application is abruptly ended?
•
Hitting the close button is the equivalent to signing off the Telnet session.
Also, if a timeout occurs, the session is ended. It is expected that good
programming techniques can trap for this error condition and, indeed,
other errors conditions, allow the application to end gracefully. This is
discussed further in Section 5.7.1.3, “Non-Programmed Sign Off” on
page 205.
•
Jumping to another link does not end your session, but if your history list
becomes too large, you cannot get back to your session. The “keys” to
your session are lost if your last Workstation Gateway window drops off
your history list; your session will time out. You can bookmark the page
and jump back to it (if the session has not timed out). However, the
bookmark is only good for the duration of the Workstation Gateway
session.
5.3.2 Workstation Gateway Server Jobs
The Workstation Gateway server is organized into:
•
A single parent job that listens and accepts connections from HTTP browser
clients. It is important to note that the port used by Workstation Gateway is
different from the port of the HTTP server because the Workstation Gateway
Server is a new type of server for which there is no well-known port. The
parent job has only one function, to hand off connection requests to child
jobs.
•
One or more child jobs: A child job performs the actual work to satisfy the
client connect request. The number of jobs actually started can vary as
previously discussed.
The benefit of this technique is that it allows the AS/400 system to do a
multiplexing of connections within a single batch job.
5.3.3 Using Workstation Gateway
Now that we know what an HTML gateway does, let′s see some examples of the
translation from text-based 5250 panels to something a Web client can see and
use. For this, we are going to show you some OS/400 displays that have been
translated to HTML.
1. Sign On:
Figure 81 on page 178 shows a portion of the traditional AS/400 sign-on
display converted now to HTML and displayed on a Netscape client. Note
Chapter 5. HTML Gateway Implementation
177
the functionality is really no different than with a normal text-based 5250
emulator.
Figure 81. The AS/400 Sign-on Display Seen by the Workstation Gateway
The URL that your Web client needs to specify to evoke the Workstation
Gateway support looks similar to the following example:
http://hostname:5061/wsg
Where:
178
HTTP:
The Workstation Gateway uses the HTTP protocol.
Hostname
This identifies the system where the request goes. This can be
just the host name or the fully-qualified host name with domain.
:5061
5061 is the default well-known port for the Workstation Gateway
server. You must specify this port because your Web client
tries to connect to port 80 by default if you fail to override this.
Unleashing AS/400 Applications on the Internet
WSG
Means using the HTML Workstation Gateway function. WSG
can be upper or lower case. If only uppercase works, this
indicates that perhaps the latest PTF is not installed on your
AS/400 system.
For more information about the logon exit programs, please see Section
5.4.4, “Logon Exit Programs” on page 191. However, if a logon exit program
is being used, the URL looks similar to:
http://hostname:5061/wsg/QAPP0100
Where:
/QAPP0100
The prefix that indicates that exit point information follows.
QAPP0100 can be either upper or lower case.
?exit_information
This is used for the optional parameters that can be used to
pass information from the client to the Workstation Gateway
server running on the AS/400 system. Characters following the
/QAPP0100 are interpreted as parameters to be passed to the
server job. For the initial connection, these parameters can be
a USERID and password used to direct the new client directly to
an AS/400 application without the need to sign on to the AS/400
system.
Save State Information
Once the session has been established, what follows after the WSG in the
URL is information to allow the AS/400 system to route this display to the
proper Workstation Gateway server. This is because the AS/400 system
must save state while using a protocol such as HTTP that does not save
state! For example, the URL used to save state looks similar to:
http://hostname:1384/WSG/057782/QTMTWSG/QTWSG00950
Where:
1384
The TCP/IP allocated for the duration of this client session.
057782
The AS/400 job number allocated to this client session.
QTWSG00950
The AS/400 job name allocated to this client session.
2. Command Entry:
Figure 82 on page 180 shows the Command Entry display for the Netscape
client.
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179
Figure 82. The Command Entry Display Seen by the Workstation Gateway
3. Work with Active Jobs:
Figure 83 on page 181 shows the Work with Active Jobs display for the
Netscape client.
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Unleashing AS/400 Applications on the Internet
Figure 83. The Work with Active Jobs Display Seen by the Workstation Gateway
5.4 Application Development with Workstation Gateway
There are various ways of enabling or developing applications for use with
Workstation Gateway:
•
Simply use an existing application ″as is″. This means using all of the
existing DDS displays, logic, and security.
•
Enhance existing applications using the new DDS HTML keyword by adding
some HTML to existing displays.
•
Create new displays using primarily the new DDS HTML keyword. Perhaps if
you only want four or five displays being used over the Internet, you can
code just these displays.
•
Create new applications designed specifically for use through Workstation
Gateway.
Chapter 5. HTML Gateway Implementation
181
•
Create Logon Exit programs that bypass the AS/400 sign-on display.
When designing or using your application with Workstation Gateway, try and
ensure that you keep inside of Workstation Gateway control. That is, do not go
off into the ″HTML world″ by providing links to other pages. This may lead to
page synchronization problems or the application being stopped by the
Workstation Gateway timing out.
5.4.1 Existing Applications (Display Files)
Your existing display files need not be changed. You can use all DDS
specifications as you did before. The DDS becomes (when compiled) a 5250
data stream. This means that the DDS keywords such as DSPATR(UL), BLINK,
CHECK, and so on are translated in a coded string of data. In this data string,
each field is preceded by one or more attribute bytes. This information makes a
field such as a customer name underlined, protected, or blinking.
The AS/400 system (or more precisely, the Twinax workstation IOP (input/output
processor)) sends out this generated 5250 data stream to your 5250
“green-screen”. The hardware of your display interprets this stream of data and
produces a protected, underlined, or blinking field on your display.
This is how it works today. With V3R2 and V3R7, the Workstation Gateway
intercepts this 5250 data stream and converts it ″on the fly″ to an HTML data
stream. Let′s look at an example to make it more comprehensive.
First, we show you a simple DDS example of a display and how it looks on a
5250 workstation (″green-screen″).
Note: This DDS example is not using any new techniques or HTML keywords.
Columns . . . :
1 71
Edit
ITSOIC400/DDSS
SEU==>
WSGDSP
FMT DP.....AAN01N02N03T.Name++++++RLen++TDpBLinPosFunctions++++++++++++ ++++++
0012.00
A
R DSPR2
0013.00
A
2 34′ ITSO Company′
0014.00
A
3 25′ Customer Comment +
0015.00
A
Inquiry System′
0016.00
A
0017.00
A
6 24′ Name : ′
0018.00
A
FNAME_X
25
O 6 32
0019.00
A N02
7 22′ E-mail : ′
0020.00
A N02
EMAIL_X
30
O 7 32
0021.00
A N02
8 20′ Address1 : ′
0022.00
A N02
ADDRESS1_X
25
O 8 32
0023.00
A N02
9 20′ Address2 : ′
0024.00
A N02
ADDRESS2_X
25
O 9 32
0025.00
A N02
10 24′ City : ′
0026.00
A N02
CITY_X
25
O 10 32
0027.00
A N02
11 23′ State : ′
0028.00
A N02
STATE_X
3
O 11 32
F3=Exit
F4=Prompt
F16=Repeat find
F5=Refresh
F9=Retrieve
F17=Repeat change
F10=Cursor
F11=Toggle
F24=More keys
Figure 84. DDS Source for Customer Comment Inquiry Display
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Unleashing AS/400 Applications on the Internet
Note: If you are not familiar with DDS programming, we recommended that you
consult the following publications:
•
•
DDS Reference , SC41-3712-01.
Application Display Programming , SC41-3715-01.
The preceding DDS looks the same as this on a 5250 display station:
ITSO Company
Customer Comment Inquiry System
Name
E-mail
Address1
Address2
City
State
Zipcode
Country
Phone
:
:
:
:
:
:
:
:
:
Vera Small
[email protected]
123 South Center Street
Rochester
MN
12345
USA
507-2895300
Comment : This is only a simple test! We can use this sampl
e to show you how easily you can use Workstation Gateway in the Internet world! It
is great for all of the AS/400 customers!!
Press ENTER to inquiry again
Figure 85. Customer Comment Inquiry DDS on the Traditional Text 5250 Display
Now let′s see how the Workstation Gateway made out of our DDS specifications
looks. Figure 86 on page 184 shows the result of the 5250 data stream
conversion process. Note that this does not mean that you had to recompile the
display file. The Workstation Gateway did this automatically ″on the fly″ for you.
When the Workstation Gateway detected that the terminal that receives the 5250
data stream is a ″virtual terminal″ (that is, a Web client), the 5250 data stream
was converted to the HTML data stream.
Note: To view the HTML behind a Web page, most browsers have a viewing
option. For Netscape, use the View... Document Source... menu item, and for
Internet Explorer use the View... Source... menu item.
Chapter 5. HTML Gateway Implementation
183
<HTML>
<HEAD>
<TITLE>AS/400 Workstation Gateway </TITLE>
</HEAD>
<BODY>
<FORM METHOD=″POST″ ACTION=″http://9.5.69.208:1029/WSG/003816/QTMTWSG/
<INPUT TYPE=″HIDDEN″ NAME=″SESSION″ VALUE=″ / A27CDCB57704125F/3B35D6E8″>
VALUE=″Enter″><INPUT TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/
NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VALUE=″Page Up″>
VALUE=″Close″><INPUT TYPE=″SUBMIT″ NAME=″SPECIALS″ VALUE=″Refresh″>
VALUE=″Style″>
<CENTER><H3>AS/400 Workstation Gateway</H3></CENTER>
<HR>
<SELECT NAME=″-General-″ SIZE=1><OPTION SELECTED VALUE=″-NONE-″>-Gener
VALUE=″@C″>Clear<OPTION VALUE=″@[email protected]<″>Record Back<OPTION VALUE=″@x″>PA1
VALUE=″@[email protected]″>Test Request<OPTION VALUE=″@[email protected]″>Host print screen<OPTION
VALUE=″@[email protected]@E″>Sign off<OPTION VALUE=″@c″>F12<OPTION VALUE=″@3″>F3</
VALUE=″@H″>Help</SELECT>
ITSO Company
Customer Comment Inquiry System
Name : Vera Small
E-mail : [email protected]
Address1 : 123 South Center Street
Address2 :
City : Rochester
State : MN
Zipcode : 12345
Country : USA
Phone : 507-2895300
Comment : This is only a simple test“ We can use
e to show you how easily you can use Workstation Gateway in the Internet
is great for all of the AS/400 customers″
Press ENTER to inquiry again
<INPUT TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/BUTTON.999-999=
NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VALUE=″Page Down″>
Up″>
<INPUT TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/BUTTON.999-999=
NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VALUE=″F2 ″><INPU
TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VAL
VALUE=″F5 ″><INPUT TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/BUT
NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VALUE=″F7 ″><INPU
TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VAL
VALUE=″F10″><INPUT TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/BUT
NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VALUE=″F12″>
<INPUT TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/BUTTON.999-999=
NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VALUE=″F14″><INPU
TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VAL
VALUE=″F17″><INPUT TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/BUT
NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VALUE=″F19″><INPU
TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VAL
VALUE=″F22″><INPUT TYPE=″SUBMIT″ NAME=″ / A27CDCB57704125F/3B35D6E8/BUT
NAME=″ / A27CDCB57704125F/3B35D6E8/[email protected]″ VALUE=″F24″>
</PRE>
</FORM>
</BODY>
</HTML>
Figure 86. A Portion of the HTML Automatically Generated by the HTML Gateway
Finally, let′s see how this looks on a Netscape Web browser and also an
example of how a subfile window looks.
Note: The result you see on a Web browser is totally dependent upon how you
configured the browser. If you choose another font, another background color,
or another font size, the actual appearance of your HTML data stream on your
PC might look quite different from our example.
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Unleashing AS/400 Applications on the Internet
Important
Workstation Gateway displays messages to the client using white colored
text; if the user changes the browser background to white, no systems′
messages are seen.
Figure 87. Display of Customer Master Record through Workstation Gateway
Chapter 5. HTML Gateway Implementation
185
Figure 88. Display of Subfile Record through 5250-HTML Gateway
5.4.2 DDS to HTML Conversion
The Workstation Gateway formats the 5250 display according to the following
basic rules:
1. The display is shown as 80-column pre-formatted text.
2. Blank lines are omitted to reduce the vertical size of the display image in the
browser.
3. 5250 input fields are translated into HTML INPUT tags with the same field
length as the 5250 field.
•
186
If an input field is longer than 160 characters, the field is translated into
an HTML TEXT area that is 80 columns long and has enough lines to
contain all the input text needed.
Unleashing AS/400 Applications on the Internet
•
If an input field is between 60 and 160 characters long, it is shown as an
input field with 60 visible characters and a maximum length of the 5250
field size.
4. Function key tags recognized in the function key area of the display are
added to the “menu” items at the top of the document.
5.4.3 DDS HTML Support
The Workstation Gateway support allows the insertion of HTML tags into the DDS
of a display file. This allows us to utilize the graphic capabilities of a Web
browser with only minor changes to the existing DDS. For example, a customer
can add graphics through the IMG HTML tag to an existing display file and
display a graphic image along with the display.
Note: These HTML tags are only inserted into the data stream that flows to a
terminal if the device query indicates that the device is a PC (or more precisely,
an AS/400 5250 Workstation Gateway virtual terminal). Otherwise, the HTML
tags are ignored for normal displays.
This simplifies and eases the handling of display files because only one source
is needed for Web browsers, and “green-screens”.
5.4.3.1 The New DDS Keyword
There is a new DDS keyword, HTML (HyperText Markup Language). This
field-level keyword can be treated the same as a usual constant. Two things are
different from a common constant. First, you have to put the new keyword HTML
before the constant, and second, the “constant” itself must consist of an HTML
string that must use the HTML syntax.
Let′s take a look at a DDS example with HTML statements.
Chapter 5. HTML Gateway Implementation
187
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
DSPSIZ(24 80 *DS3)
CA03(03)
CA12(12)
R DSPREC
EMPNUM
02
02
02
02
02
02
02
02
FIRSTN
LASTN
PHONO
02
2 22′ IBM Rochester Personnel Inquiry System′
3 4HTML(′<IMG SRC=″ / / INTERNUT/+
/ITSOIC.400/AS400.GIF″ > ′ )
3 4HTML(′<Table BORDER>′ )
3 4HTML(′<TR>′ )
3 4HTML(′<TH COLSPAN=2></TH>′ )
3 4HTML(′<TH>Table Demo</TH>′ )
3 4HTML(′ < / TR>′ )
3 4HTML(′<TR ALIGN=CENTER>′ )
3 4HTML(′<TH ROWSPAN=2></TH>′ )
3 4HTML(′<TH>First</TH>′ )
3 4HTML(′<TD>Row</TD>′ )
3 4HTML(′ < / TR>′ )
3 4HTML(′<TR ALIGN=CENTER>′ )
3 4HTML(′<TH>Second</TH>′ )
3 4HTML(′<TD>Row</TD>′ )
3 4HTML(′ < / TR>′ )
3 4HTML(′ < / TABLE>′ )
3 4HTML(′<IMG ALIGN=TOP +
SRC=″ / / INTERNUT/+
/ITSOIC.400/RHAND.GIF″ > ′ )
3 4HTML(′<A HREF=″http://internut/+
class/wsg000.htm″>Link-Here</A>′ )
6 20′ Please Input Employee Number : ′
6S 0B 6 52
9 26′ First Name : ′
20 O 9 42
10 26′
Last Name : ′
20 O 10 42
11 26′ Phone Number : ′
7S 0O 11 42
14 25′ Not found - Please press ENTER′
DSPATR(RI)
21 5′ F03=Exit′
21 30′ Press ENTER to inquiry again′
Figure 89. Sample 5250 DDS Enhanced with the HTML Tag
Note: The plain text is mixed with HTML tags.
Important
The IMG SRC tag must have a fully qualified URL, and the HTTP server must
be running for Workstation Gateway to serve images. Basically, the
Workstation Gateway server re-directs all links for HTTP type objects such as
images to the local server (meaning that it has to be running on the same
AS/400 system as the Workstation Gateway server).
Now, let′s take a look at the display output of the sample DDS with the preceding
HTML tags. You can see there is a ″Link-Here″ which corresponds to the HREF
in DDS. Also, a ″Table Demo″ is related to the TABLE tags.
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Unleashing AS/400 Applications on the Internet
Figure 90. Link, Table, and Images Imbedded in DDS
If you have installed the sample code from the Cool Title About the AS/400 and
Internet , this display file and the program for it are in the library ITSOIC400. The
name of the file is SHTMLD and its source is in the source file QDDSSRC. The
name of the program is SHTMLR and its source is in QRPGSRC.
Note
•
Using CRTDSPF and setting the ENHDSP (Enhanced Display) parameter
to *NO, the HTML keyword is ignored; hence, it is possible to turn off the
HTML without recompiling the DDS.
•
You can also use variable substitution in DDS and pull data from a DB
file and merge it with the HTML keyword such as in a table.
Chapter 5. HTML Gateway Implementation
189
What are HTML Tags?
HTML documents consists of plain text interspersed with markup commands
called tags. The tags are instructions to the browser software on how to
display the text. They are represented by strings enclosed in <angle
b r a c k e t s > . See Section 2.9.1, “Hypertext Markup Language (HTML)” on
page 25 for more information about HTML.
Another thing to mention is that in the preceding example, ″normal″ DDS
keywords and HTML specifications are used within one source. HTML is a
procedural language where the order of the tags determines when they are
processed. Row and column have no meaning in such a language. In this case,
the row and column are used to determine the order in which the HTML tags are
sent to the browser. For example, an HTML keyword at row 2/column 4 appears
before an HTML keyword at row 2/column 6. See Appendix B, “HTML Gateway
Code Examples” on page 263 for more examples of DDS usage and overlap
issues.
With the HTML keyword, constant fields that have the same row and column
value are processed in the order in which they appear in the DDS source.
Please notice that you can use any HTML tag except <HTML>, </HTML>,
<HEAD>, </HEAD>, <TITLE>, </TITLE>, <BODY>, and </BODY>
because all of the preceding tags are used by HTML Gateway to build the overall
structure.
Note
•
It is possible to use the <PRE>...</PRE> tags but these tags are also
used by Workstation Gateway to generate the HTML page.
•
It is not possible to add certain HTML tags to the header section of the
generated HTML page.
5.4.3.2 The HTML Keyword Syntax
The new HTML specification can have two formats:
HTML(′ datastring with a valid HTML tag′ )
or
HTML(&program-to-system-field)
A parameter is required after an HTML keyword. This parameter can be a valid
HTML tag enclosed in single quotes or a program variable. The
program-to-system field can be any legal length and has to be alphanumeric (A
in position 35).
Note: The syntax of the HTML tag is not syntax checked by the DDS compiler.
The browser that receives the HTML sequence performs syntax checking. It is
important, therefore, that you test the display on the browser to verify the correct
HTML and DDS syntax.
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Unleashing AS/400 Applications on the Internet
5.4.3.3 Limitations and Restrictions
The following keywords are not allowed with the HTML keyword:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
COLOR
DATE
DFT
DSPATR
EDTCDE
EDTWRD
HLPID
MSGCON
NOCCSID
OVRATR
PUTRETAIN
SYSNAME
TIME
USER
The HTML keyword is not allowed on a field in a subfile record.
5.4.4 Logon Exit Programs
An application logon exit program (QAPP0100) allows us to bypass the AS/400
Sign-on display and invoke an application program directly without the client
browser having to send a user profile or password. This allows the customer
the option of providing any application to client browsers without requiring a sign
on. This has the added benefit of removing the command line for this client.
This is done by calling a customer program that authenticates the client request
and provides sign-on information to the Workstation Gateway Server.
The Workstation Gateway Server uses the output of the customer′s user exit and
performs the sign-on action on behalf of the client browser.
When the user exit is given control, it may perform any desired validation using
the supplied Internet Protocol address and any of the supplied operation-specific
information extracted after the ″/WSG/QAPP0100″ string in the URL. Setting the
″Allow Operation″ output determines whether the automatic logon is performed,
or whether an error message is returned to the client browser.
If the operation is allowed, the user exit must return the user profile, password,
current library, and program. All output must be non-NULL or else an error is
returned to the client browser.
Only one exit program can be registered for the exit point QAPP0100. The
TCP/IP Configuration and Reference , SC41-3420-03, contains information about
the registration of this exit point.
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Table 16. User Exit Program Extensions
Parameter
Description
In/Out
Type
1
Operation Specific Information
Input
Char(*)
2
Length of Operation Specific Information from
URL
Input
Binary(4)
3
Client IP (Dotted Decimal) address
Input
Char(15)
4
CCSID
Input
Binary(4
5
Allow Operation
Output
Char(1)
6
User Profile
Output
Char(10)
7
Password
Output
Char(10)
8
Current Library
Output
Char(10)
9
Program to call
Output
Char(10)
10
Initial menu
Output
Char(10)
11
Session end URL
Output
Char(300)
Note: Do not use the Client IP address, parameter 3, as a means of identifying
authorized users to your system. It is possible for IP addresses to be “spoofed”
or copied.
Note: Session end URL Output parameter 11 is accepted as an extension to
User Exit point QAPP0100 for Workstation Gateway. It must be a fully-qualified
URL (up to 300 characters, trailing blanks stripped), for example:
http://httpserver/directory/some.html
This URL link is sent to the Web browser whenever the Workstation Gateway
session is ended. If no URL is specified, the default action is to post timing
statistics.
One trick you might want to do is have the session end URL arrive as part of
parameter 1 (operation specific information). The exit program can simply echo
parameter 1 out through parameter 11. The following example illustrates this
concept:
<A href=″http://wsgserver:5061/WSG/QAPP0100?http://httpserver/return.html″>GO!</A>
This is useful if you want to return the HTML form that initiated the Workstation
Gateway session, or if you want to jump to another HTML form when you are
done with the Workstation Gateway session.
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IMPORTANT!
Try to ensure that your exit programs do not allow users access to any of the
following functions:
•
•
•
•
•
Command Entry line
STRPASTHR
Attention Key
System Request
F3 exit key or similar (if possible, do not use F-keys, for better ease of
use and better security!)
Where possible:
•
•
•
•
•
•
Use a USER profile that has no rights or authority to sensitive information
or programs.
Prevent the sign-off/sign-on display from being shown to the user.
Trap all errors and, if in doubt, sign off.
Only allow sign off to the appropriate Workstation Gateway profile.
Do not forget access through help displays.
Code an exit URL so the client is passed back to a useful HTML page.
Above all, test your exit program and application and try to look for all the
access points into your system through the Workstation Gateway.
Use the following steps to use the Exit Program:
1. Code your Exit Program. You can use the sample program provided.
2. End the Workstation Gateway Server by using the ENDTCPSVR
SERVER(*WSG) command.
3. Change the workstation gateway attribute for using the Exit Program with the
CHGWSGA DSPPGN(*NO) command.
4. Register your Exit Program by using the WRKREGINF
EXITPNT(QIBM_QTMT_WSG) command. Use option 8 to add your exit
program.
5. Start the Workstation Gateway server by using the STRTCPSVR
SERVER(*WSG) command.
6. Open a URL in Web browser as http://hostname:5061/WSG/QAPP0100?xxxxx
where xxxxx is any string that you want a user to type in so you can use
your Exit Program for security checking.
Note
•
Only one exit program can be registered for exit point QAPP0100.
•
If you get an exception error on the browser (such as CEE9901), it might
be worth checking the object authority for the exit program. Use the
WRKOBJ OBJ(QUSRSYS) command, option 2, and change the *PUBLIC
user authority from *USE to *CHANGE.
•
Also check the job log for the Workstation Gateway jobs using
WRKACTJOB and look for user profile QTMTWSG under the QSYSWRK
subsystem.
•
When restarting the Workstation Gateway server, allow several minutes
for the stop and start process to take place!
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5.4.4.1 Sample Exit Program
This sample exit program uses one of the input variables (IP address of the
remote host system) from the HTML Gateway system program to check if a Web
browser user has the right to use the HTML Gateway function.
You can find the source of this sample program in the QILECSRC source file in
the ITSOIC400 library.
From Web browser, open the URL http://hostname.domainname:5061/WSG/QAPP0100.
You can bypass the sign-on display and go into the command entry display.
Note: Please see Appendix B, “HTML Gateway Code Examples” on page 263
for the code listings of exit programs in C, RPG, and CL languages.
5.5 Tips for using Workstation Gateway
The following tips or hints might help you make better use of Workstation
Gateway function:
1. The Workstation Gateway function is not a substitute for an original
workstation connection.
2. The performance of using Workstation Gateway is not as good as using a
traditional 5250 connection such as tn5250 through Telnet. Care should be
given when sizing an AS/400 system, as this kind of 5250 to HTML
conversion is not done without extra cost in CPU terms. See Chapter 8,
“Internet Application Performance” on page 237 for more details on
Workstation Gateway performance statistics and possible improvements
(tuning).
Performance Tip
Preformatted text is rendered on the screen faster by the browser than
formatted text (for example, tables). In addition, preformatted text
produces a smaller HTML file that can be transferred quicker.
3. With the exception of the character input fields, always use the mouse to
click on the function key you want instead of using a key on the keyboard
such as Enter or F3.
4. Context sensitive help versus general help. The AS/400 system considers
the ″?″ character as the first character of an input field to be a ″cursor move″
request. The request moves the cursor to that input field, thus allowing you
to use the F1 (contextual help) or F4 (prompt) buttons. In fact, any function
key button can be used, not just F1 and F4 buttons.
The AS/400 system does not keep the ″?″ in the input field upon return from
the function key button action. Please note that this help function applies
only to input fields. If you have help defined for some output fields, there is
no way to get to it.
For general help, the Help menu pull-down (or button) first moves the cursor
to display row 1, column 1, and invokes the help command. This is not the
same as context sensitive help. This is because the cursor is moved to a
position that is probably context insensitive before invoking help. This also
means using the Help menu pull-down (or button) does not normally give the
help for the home (default) input field, and the ″?″ invocation mechanism
may be needed to force this help to appear.
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5. Different Web browsers may have a different display output when handling
the same HTML tags.
Recommendation
Try and test your application on as many browsers as possible, at least
Netscape, Internet Explorer, and Mosaic based browsers such as IBM′ s
Web Explorer.
6. After you have established a session between your Web client and the
AS/400 HTML gateway server function, you might want to start a Telnet or
use STRPASTHR to connect to another remote host. This function was not
formally tested, but it seems to work in the ITSO network.
Note
It is not recommended that you enable this functionality for public Web
sites.
7. Never use previous and next page function in a Web browser as a way to
jump into the application flow from that page. We suggest turning off
caching on the Web client to enforce this suggestion.
8. No text assist is available.
9. You cannot use applications that automatically update the 5250 display
without the client using an aid key. An example is the performance tools
WRKSYSACT command when you use the automatic display refresh option.
10. Style button:
The action bar (top row of buttons) has a style button that toggles the style
used for the F1-F24 buttons. One mode shows displays F1-F24 as two rows
of buttons at the bottom of every display. This takes up more display space,
but has the advantage of letting you quickly submit the form.
The other mode puts F1-F24 into a Function menu pull-down next to the
General menu pull-down. This makes submitting the F1-F24 keys a two-step
process (select menu item, then press Enter), but has the advantage of less
display clutter and a faster display by the browser.
11. NLS code pages:
Special characters and code pages can be requested by each individual
client. Translation is usually from the EBCDIC CCSID of your AS/400 system
to the ASCII CCSID specified in the CHGWSGA CCSID parameter. So, if the
CHGWSGA CCSID parameter is changed, the EBCDIC CCSID default value
also changes, since we get the ″best fit″ EBCDIC CCSID from the configured
ASCII CCSID. This default can be overridden by each user. Examples for
Sweden are:
No user exit:
http://as400.endicott.ibm.com:5061/WSG-SWB
http://as400.endicott.ibm.com:5061/WSG-SWI
http://as400.endicott.ibm.com:5061/WSG-SFI
User exit:
http://as400.endicott.ibm.com:5061/WSG-SWB/QAPP0100
http://as400.endicott.ibm.com:5061/WSG-SWI/QAPP0100?any_string_data
http://as400.endicott.ibm.com:5061/WSG-SFI/QAPP0100
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Refer to Appendix C in the National Language Support , SC41-3101, for a table
of supported keyboard strings that can be used.
Here are the rules to which the Workstation Gateway converts EBCDIC to
ASCII:
•
The Workstation Gateway builds the HTML in code page 037 using only
invariant characters for the tags and control words.
•
The 5250 application sends the data/character in the code page that it
determines independent of the Workstation Gateway.
•
Once the document is built, it is converted to ASCII in the CCSID
specified in the following order:
a. MIME header specified by the remote browser
b. Overridden by the interactive subsystem (WSG-xxx)
c. WSG attribute (CHGWSGA command)
d. The system default CCSID
12. If the remote Web client is signing on to the AS/400 system with a unique
user profile (not a shared anonymous profile), you can still use the OUTQ
parameter of that user profile to direct all of the printouts to a single queue.
This queue, in turn, can be a remote output queue that uses TCP/IP to route
the print data back to any printer in the network (most likely, the printer
sitting right next to the user′s desk). Many IBM manuals and redbooks have
instructions on how to configure such remote output queues. One in
particular that includes sample configurations is Printer Device Programming ,
SC41-3713-01.
13. Log all accesses made by the Workstation Gateway (this is a configuration
item). All accesses to the Workstation Gateway are recorded in physical file
QATMTLOG in library QUSRSYS. Further information can be found in TCP/IP
Configuration and Reference , SC41-3420-04.
5.6 I/NET′s Webulator/400
Webulator/400 is the 5250-HTML gateway from I/NET, and is used in conjunction
with either Web Server/400 or Commerce Server/400. You can use your current
applications or even develop new Web applications using such tools as RPG,
COBOL, DDS, ILE C, and so on. More information about I/NET and their AS/400
Web serving products can be found at the following URL:
http://www.inetmi.com/
5.6.1 Getting Started
Full installation and configuration details of the Webulator/400 product can be
read in the Webulator/400 User Guide , which can be found at the following URL:
http://www.inetmi.com/pubs/webulate/usrguide.htm
Or you can read the documentation online, which may require you to start the
server to access the links. In particular, the following items are discussed in
more detail in the Webulator/400 documentation:
•
•
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User profiles
Unleashing AS/400 Applications on the Internet
•
•
•
Virtual terminals
Programming
System security values and auditing
5.6.1.1 Configuring Webulator/400
1. Install the appropriate Web Server/400 or Commerce Server/400 and
Webulator/400 code.
2. Create a Webulator/400 alias (both servers ship a default Webulator alias
named /WWW5250/). To add a new alias, you can run the WRKWWWALS
command.
3. Run the CHGWWWCFG command to enable Webulator/400:
a. Set the Directory Based Configuration File Field (ACCGBLFILE):
The easiest way to set up Webulator/400 is to use the sample Directory
Based Configuration file that is shipped with the Webulator/400 product. You
can use this file by setting the directory-based configuration field to
/WWWSERV/CFG/WBLMACC.CFG.
Note: If you already have an entry in the directory-based configuration field,
it is recommended that you temporarily replace your current configuration
file with the Webulator/400 sample Directory Based Configuration file. This
allows you to test and get familiar with the functionality of Webulator/400.
After you feel comfortable with its functionality, you can modify your existing
Directory Based Configuration file to include the desired new entries for
Webulator/400.
Note: All Webulator/400 configuration values are set to their default values
when using this file.
b. Set the Webulator/400 User File Path Field (WBLUSRFILE):
You must set the path of the Webulator/400 user file if you plan to take
advantage of the automatic sign-on capabilities of Webulator/400. The
easiest way to set up Webulator/400 to use automatic sign on is to reference
the sample user file that is shipped with the Webulator/400 product. This file
can be used by setting the Webulator/400 User File Path field to
/WWWSERV/CFG/AUTH/WBLUSR.CFG.
Note: This file is shipped with no entries since it is not possible to know the
USERIDs or passwords on your system. You must add your own entries to
this file using the WRKWBLUSR command before it is useable by
Webulator/400.
Note: It is beneficial to use the sample user file because of the authority
settings that are shipped with this file.
c. Set the Ma x i m u m Webulator/400 Sessions Field (WBLMAXSSN):
You can optionally set the maximum number of simultaneous Webulator/400
sessions that are allowed. If you do not specify this entry, a default of 20
sessions is used.
d. Set the Disable Webulator/400 Field (DISABLEWBL):
You must set the Disable Webulator/400 entry to *NO to configure the server
to automatically start Webulator/400 during its startup process.
4. Evaluate the Sign-on Method:
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The sample Directory Based Configuration file
(/WWWSERV/CFG/WBLMACC.CFG) that is shipped with Webulator/400
contains a root directory entry with a sign-on method of sign-on display.
Note: “Sign-on display” was chosen because of its ease of setup, but it
does have some potential security considerations. If you are not comfortable
having a sign-on display available even for a short period of time, you should
change the sign-on type to a different value before restarting or reconfiguring
Web Server/400. This value can be set through the sign-on method field
through option 10 of the WRKWWWDIR command or directly through the
CHGWBLCFG command.
Valid Sign-On Methods
Method
Result
SIGN-ON DISPLAY
The standard AS/400 sign-on display is shown.
USEAUTHENTICATION Presents a dialog box asking for your USERID
and password. These values are encoded before
being sent to the server, using the base64
encoding of MIME(UUENCODED).
USER
Automatically logs onto a specific user profile.
The first display for that AS/400 user profile is
shown.
DISABLED
Prevents logging-in. An error message is sent to
the browser when you try to access the URL.
5. Add Additional Webulator/400 Directory Entries
The sample Directory Based Configuration file
(/WWWSERV/CFG/WBLMACC.CFG) that is shipped with Webulator/400
contains only the Webulator/400 root directory entry and no child directories.
You can optionally add more Webulator/400 directory entries by running the
WRKWWWDIR command.
Note: All Webulator/400 directory entries must start with
/*META/WEBULATOR/. Therefore, the Webulator/400 root directory is always
named /*META/WEBULATOR/. If you want to add a new directory entry
below the Webulator/400 root, you can add an entry such as
/*META/WEBULATOR/STATUS/.
Note: By creating additional directories, you can have multiple URLs that
have different characteristics (such as which user is automatically signed
on).
6. Check AS/400 Virtual Terminals:
Verify that the AS/400 system value QAUTOVRT is at a large enough number
so that Webulator/400 can automatically create additional virtual terminal
devices if needed.
7. Start your Web server:
Start either Web Server/400 or Commerce Server/400. It starts
Webulator/400 during its startup process.
Note: If your server is already started, you can run the Set WWW
Configuration Values (SETWWWCFG) command, which reconfigures the
server, which, in turn, starts Webulator/400. Note that in the future when you
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reconfigure Webulator/400, the new configuration values take effect for all
new sessions only.
5.6.1.2 Starting Webulator/400
The following steps help you determine if Webulator/400 has been configured
properly for access. Having started the server, you must also be running a Web
browser on a workstation connected to the AS/400 system using TCP/IP.
1. Access the Webulator/400 Root URL through:
http://your.system.name/WblAliasName/
where:
your.system.name Your AS/400 system′s TCP/IP host name or IP address.
WblAliasName
Is an alias whose SRCTYPE is *WEBULATOR.
Note: You can view all of your current aliases by running the WRKWWWALS
command.
Example
Assume that your HOSTNAME is www.xyz.com and your *Webulator alias
name is /WWW5250/. The name of your Webulator/400 root URL is:
http://www.xyz.com/WWW5250/
2. If you added additional Webulator/400 directory entries using the
WRKWWWDIR command, you should try to access their URLs also.
Note: To determine how to access child URLs, you must look at the names
of your directory entries. Since all Webulator/400 directory entries must start
with the Webulator/400 root directory name of /*META/WEBULATOR/, you
can ignore all entries that do not meet this criteria.
Example
Assume that you have the following Webulator/400 directory entries:
/*META/WEBULATOR/
/*META/WEBULATOR/STATUS/
The first entry is the Webulator/400 root directory and the second
directory is a child below the root directory. To determine the name of
the URL to access this child directory, you need to strip off the
Webulator/400 root component from the directory name. This leaves us
with the name of the child directory entry (STATUS/). You must append
the name of the child directory entry to the URL of the Webulator/400 root
to get the correct URL for the child directory entry. Assuming that the
root directory URL is:
http://www.xyz.com/WWW5250/
the URL for the child would be:
http://www.xyz.com/WWW5250/STATUS/
3. Check for expected configuration values to ensure that the Webulator/400
URLs are using the configuration values you are expecting.
Note: If any are not, they are either using a default value or are inheriting a
value from one of their parent directories. If a directory entry is inheriting an
undesirable configuration value, you must define a new value in the current
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199
directory to override the inherited value. These values can be set through
options 8, 9, and 10 of the WRKWWWDIR command or directly using the
WRKWBLROW, WRKWBLPRS, and CHGWBLCFG commands.
5.6.2 Webulator/400 Sign-On Methods
The following section describes the detail for configuring the sign-on parameters.
The parameters are:
1. Method. This can be one of User, Screen, UseAuthentication, or Disabled.
•
User causes the system to automatically sign on with a specific user
name. This is the most secure way to configure Webulator/400 because
you have control over what AS/400 user profiles people are allowed to
sign on with. If this is specified, it must be followed by a UserName,
which is described later.
•
Screen causes users to be presented with an AS/400 sign-on display.
They may type in the AS/400 user and password they want to use to sign
on. This is less secure because the AS/400 user and password are sent
over the TCP/IP network between the browser and the server. It is
recommended that this only be used over internal networks unless
secured with SSL and Commerce Server/400. If Commerce Server/400 is
configured to use SSL for Webulator/400 sessions, all data, including
user IDs and passwords is encrypted.
•
UseAuthentication uses authentication information sent from the browser
as the AS/400 user and password. This is slightly more secure than
Screen because the user and password are sent UUENCODED (while
UUENCODED text is not as obvious as “clear” text, it is not a form of
encryption and it is easy to “decode” it). You can also combine this with
access control to limit the user IDs and passwords that can be entered
for a URL. This changes the meaning of Web Server/400 required
entries; any users listed are expected to be valid user profiles instead of
entries in a user file.
•
Disabled disables Webulator access in the current directory.
Note: If no entry is provided for a directory, the parent directory′s value is
inherited. If the root directory has no entry, the default, which is Disabled, is
inherited.
2. UserName. This must be present if User was specified previously. It is the
AS/400 user that is signed on. It must have a corresponding entry in the
Webulator/400 user file.
Note: Only one entry may exist in a directory section. If more than one
entry is found, the last one is used.
•
AllowSignonOverride. This is only applicable if the method is set to User
or UseAuthentication. If set, Webulator/400 allows sign-on display fields
to be overridden by URL options.
•
IgnoreSignonOverride. This is only applicable if the method is set to
User or UseAuthentication. If set, Webulator/400 does not allow sign-on
display fields to be overridden by URL options.
3. Webulator User Entry. Specifies a user name and password that is used for
automatic sign on by Webulator/400.
•
200
Name. This is the AS/400 user profile that users are signed on as.
Unleashing AS/400 Applications on the Internet
•
Password. This is the AS/400 password that is entered for users.
Because this is not encrypted, you should protect this configuration file
with OS/400 authority. Only the user who changes the file and the user
who starts the server needs authority to the file. The server user profile
should not have authority to this file.
Note: Multiple entries may exist in the Webulator/400 user file.
5.6.3 Using Webulator/400
This section describes how to use the Webulator/400 from I/NET.
5.6.3.1 URL Syntax
You can specify options on the query string of the URL that initializes a
Webulator/400 session to change the behavior of that interactive Webulator/400
session. The query string is specified on the initial URL after the complete
Webulator/400 path has been specified. It starts with a ? followed immediately
by the list of query string value pairs separated by an &. Assuming that your
Webulator/400 session URL is:
www.xyz.com/www5250
the syntax is similar to this:
www.xyz.com/www5250?KEYWORD1=VALUE&KEYWORD2=VALUE
Spaces are not allowed inside the query string; you must substitute a + for all
embedding spaces. The following query string keywords are available:
PGM
MENU
LIB
FIELD1
Allows you to specify a value for the initial program to run.
Allows you to specify a value for the initial menu to run.
Allows you to specify a value for the initial library.
Allows you to specify the value that is returned to the AS/400 system
for the first input capable field that is encountered. When this
keyword is specified, Webulator/400 simulates pressing ENTER for all
displays up to and including the first display with an input field. It is
your responsibility to ensure that the first display with an input field
can properly handle the value being passed to it.
Restrictions: The Sign-on Method value must be one of:
•
•
USER ALLOWSIGNONOVERRIDE or
USEAUTHENTICATION ALLOWSIGNONOVERRIDE
for Webulator/400 to recognize the PGM, MENU, or LIB query string keywords.
There are no restrictions on using the FIELD1 keyword.
Considerations: Care should be taken before enabling the
ALLOWSIGNONOVERRIDE feature. When this feature is enabled, it allows you to
override any of the initial sign-on values based on an HTML link.
This may be useful if you want to create a series of HTML links to some of your
most popular applications but you do not want to create separate user profiles
that have those applications as their initial program. In this case, you can use
the query string keywords to override which application is called based on the
HTML link regardless of the user profile that was used to sign on.
Note: This flexibility does not come without additional security considerations.
If you enable the ALLOWSIGNONOVERRIDE feature, any user that has access to
that URL can also override the query string keywords to run any program that
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201
their user profile has access to. Please keep this in mind before enabling this
feature.
There are no security considerations associated with the FIELD1 query string
keyword. The inclusion of this keyword on the query string is the equivalent to
the user typing it in themselves. They are not able to get access to any
additional AS/400 programs or functions by using this feature.
You may find this feature useful if you have a URL with a sign-on method of
USER that brings up an AS/400 menu as its first display. In this case, you can
create a series of HTML links to the same URL but with a different query string
FIELD1 value that automatically selects the appropriate menu option for the user.
Examples
The following examples assume that your Webulator/400 URL is:
/www.xyz.com/www5250
If you want the user to automatically start the program called MYPROG in the
MYLIB library, use the following URL:
www.xyz.com/www5250?PGM=MYPROG&LIB=MYLIB
If you want the user to automatically take option 1 from the menu called
MYMENU in the MYLIB library, use the following URL:
www.xyz.com/www5250?MENU=MYMENU&LIB=MYLIB&FIELD1=1
You can also use the FIELD1 keyword to call an initial program that accepts
dynamic parameters. Please be aware that to do this, you must give the
user access to a command line that may not always be desirable for security
reasons. Assume that the program MYPROG accepts parameters. You can
call this program with the following URL:
www.xyz.com/www5250?FIELD1=CALL+MYLIB/MYPROG+PARM(′ PARM1′ + ′ PARM2′ )
5.6.3.2 Keyboard Plugin
There is a browser plugin that provides keyboard support for Webulator/400.
Because keyboard support is implemented as a Netscape plugin, it is platform
specific and must be tested with each browser. The supported browsers are:
•
Windows 3.x
−
−
•
Netscape Navigator 2.0
Netscape Navigator 3.0
Windows 95/NT
−
−
−
Netscape Navigator 2.0
Netscape Navigator 3.0
Microsoft Internet Explorer 3.0
To complete the installation of the plugin, you must:
1. Ensure the server code is either Webulator 1.1a or you must install a
Webulator PTF.
Note: You can check your Webulator version by typing:
DSPDTAARA DTAARA(WWWSERVER/VERSIONWBL)
You can get the PTF from:
ftp://ftp.inetmi.com/pub/webulate/wbl110001.txt
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2. Download the plugin. You need to download different files for Windows 3.1
or Windows 95. The download can be found at the following URL:
http://www.inetmi.com/pubs/webulate/keyplug.htm
3. Follow the instructions provided in the documentation at the preceding site
and with the downloaded files.
Note: You must close your browser for the plugin to be recognized.
4. Configure Web Server/400 as described in the documentation.
Using the Plugin: When you enter a URL to send your browser to a Webulator
session, add the query string KEYBOARD=Y to activate the plugin. An example
URL might be:
host/www5250?KEYBOARD=Y
For usability, it is recommended that you enable JavaScript for any Webulator
URLs for which you plan to use the keyboard plugin. This attempts to
automatically set the keyboard focus to the correct form control, reducing your
need to use the mouse.
The keys F1 to F24 work as normal (press shift to use F12-F24). To cause the
AS/400 system to roll up or down, hold the Control key while pressing the Page
up or Page down key. Also, when in a multi-line edit control (text area), you
must hold down the Control key for the Enter key to be recognized. Press the
Escape key for attention and hold the Shift key down while pressing Escape for
system request.
You see a combo-box, a push button and the Webulator keyboard icon when
using the plugin. The combo-box contains the virtual keys you have defined for
the current URL. You can still limit the keys available to a user or change
descriptions through this mechanism.
Troubleshooting: There are several steps to configure and install the plugin and
if any are not correct, it will not work. Fortunately, once you have the plugin
correctly installed for a given browser, you should not need to worry about it in
the future. Possible problems might be:
•
•
The browser does not show the plugin in Help|About menu.
−
Make sure you completely shut down the browser and restart it. If you
leave even one browser window open, it does not recognize the plugin.
−
Make sure you have the correct version of the DLL. If you are using a
16-bit browser, you must have the plugin for Windows 3.x. If you are
using a 32-bit browser, you must have the plugin for Windows 95/NT.
−
Check to see if your browser is on the list of supported browsers.
Because this plugin is platform-specific, it does not work with all
browsers.
−
Make sure you copied the DLL file into the proper directory. Problems
have been seen with Netscape Navigator 2.0 recognizing any plugin
when installed on a network drive (in this case, install the browser to a
local drive).
The browser says ″Plugin Not Loaded″.
−
The browser may not be able to find the PLUGIN.WKY file. Make sure it
is in the document root and that it is available to the browser. You can
check the access log to see if the server was able to successfully send it.
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−
•
The content type may not have been set correctly. Use WRKWWDIR to
check the entry.
Everything looks fine, but pressing a key just elicits a beep.
−
You probably have loaded the beta version of the plugin, but are still
running against the test version of PTF WBL110001. Get the latest PTF
installed on your AS/400 system. The beta version of the plugin is only
compatible with the release version of PTF WBL110001.
5.7 Application Development with Webulator/400
There are a few things you should keep in mind when preparing to include your
AS/400 application on the Internet. They all involve the access and availability of
your system and its objects to the general Internet public. Keep in mind that this
applies only if you are planning to allow access outside your business (through
the Internet, or any other means). If you are maintaining a closed Intranet
system, you can follow your normal security precautions.
First, you probably want to restrict users who sign on through Webulator/400 to
the applications that you have selected for their use. This means that the user
should not be given a command line. The command line allows users to enter
commands, including commands that you may not want them to execute, such
as the CALL command to call a program or STRPASTHR to access another
system. At minimum, the SNDMSG command in the wrong user′s hands can be
a real nuisance. This includes the availability of the command line on some IBM
provided displays. An operation as simple as the WRKJOB command (to allow
the user to view and affect aspects of their individual job), while automated as
part of a menu, still has a command line associated with it.
Inquiries and simple data entry that is run through a verification and
authentication process are probably the best applications for Internet access.
These applications allow users the ability to view information about your
company and its products, as well as enter limited information to order products
or request more detailed inquiries. They also allow for the entry of order
requests that can easily be followed up or verified after the fact. If you have
chosen to perform automatic sign on or user authentication sign on for the user,
you probably do not want them to get back to a real AS/400 Sign On display.
Access to the Sign On display defeats the work you have done in restricting
access to the USERID that you have defined for Web access. It also gives the
user the opportunity to begin “guessing” the USERIDs and passwords on your
system. As a result, it is best not to include an option to sign off from your
menus (usually option 90) and application displays available to the public. Keep
in mind that this also includes the ability to sign off through help panels, whether
they were written for your application or are supplied by IBM as generic help for
the AS/400 system.
5.7.1 Signing Off
This section describes how to close a session when using Webulator/400.
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Unleashing AS/400 Applications on the Internet
5.7.1.1 Closing Confirmation
Webulator/400 allows you to determine if the user should be given a
Confirmation display after they press the Close Session command button. You
may want to set this value to YES if you want to protect users from accidentally
pressing the Close Session button and losing their session data. The Closing
Confirmation display allows the user to return back to the previous display or to
continue closing. You may want to set this value to NO if you feel the likelihood
of your users accidentally pressing the Close Session is remote or you find that
they are less likely to close a session because of the extra step involved.
5.7.1.2 Termination URL
Webulator/400 allows you to specify a Termination URL that control is transferred
to when the user ends a Webulator/400 session. This allows a transparent way
for the user to be returned to a meaningful URL when they are finished with their
Webulator/400 session. In addition to the URL, a description must be entered
that is used as the link text to your termination URL on all Webulator/400 error
messages.
5.7.1.3 Non-Programmed Sign Off
If your program does not permit a user sign off, this presents us with a
reasonable question, ″How do I end the application and the job when the
Webulator/400 session is closed by the user?″ Interestingly, the answer to that
question is to issue the “SIGNOFF” command. This is not available to the user,
but from within the application when a display error occurs identifying that the
session has been closed. Basically, you should monitor for errors whenever a
display is written to the 5250 display from your program. This can be done using
MONMSG in CL programs following any SNDRCVF statements. The contents of
the EXEC parameter are simply the command “SIGNOFF”. An illustration of this
procedure, as well as RPG and COBOL logic, can be found in the following
examples:
PGM
DCLF FILE(DSPFILE)
.
.
.
SNDRCVF RCDFMT(SCREEN1)
MONMSG MSG(CPF0000) EXEC(SIGNOFF)
.
.
.
Figure 91. CL Program Example
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205
.....CL0N01N02N03Factor1+++OpcdeFactor2+++ResultLenDHHiLoEqComment
.
.
.
C
C
C
C
C
C
C
C
*IN99
EXMFT SCREEN1
IFEQ ′ 1 ′
MOVEL′ SIGNOFF′ SGNOFF 7
Z-ADD7
SGNLEN 155
CALL ′ QCMDEXC′
PARM SGNOFF
PARM SGNLEN
END
99
.
.
.
Figure 92. RPG Program Example
ENVIRONMENT
DIVISION.
.
.
.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT DISPLAY-FILE
ASSIGN TO WORKSTATION
ORGANIZATION IS TRANSACTION
FILE STATUS IS WS-FILE-STATUS.
.
.
.
DATA DIVISION.
.
.
.
WORKING-STORAGE SECTION.
01 WS-FILE-STATUS
PIC X(2).
01 WS-SIGNOFF-VARIABLES.
05 WS-SIGNOFF-CMD
PIC X(7) VALUE ″SIGNOFF″ .
05 WS-SIGNOFF-LEN
PIC 9(10)V9(5) COMP-3 VALUE 7.
.
.
.
PROCEDURE DIVISION.
.
.
.
WRITE DISP-RECORD FORMAT IS SCREEN1.
READ DISPLAY-FILE.
IF WS-FILE-STATUS IS NOT EQUAL ″00″ THEN
CALL ″QCMDEXC″ USING WS-SIGNOFF-CMD WS-SIGNOFF-LEN,
STOP RUN.
.
.
.
Figure 93. COBOL Program Example
These examples show the logic that you may want to include in your application
to ensure the closeout of the application and completion of the job. Obviously,
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Unleashing AS/400 Applications on the Internet
other steps that may be required to complete or close a transaction in your
application are not shown here. The contents of the QDEVRCYACN system value
also determines how the application program is informed of the session
termination and may inhibit the return of error indications to the program.
5.7.2 Existing Applications
Webulator/400 allows you to choose if the AS/400 display data should be sent as
HTML preformatted text or as an HTML table.
5.7.2.1 HTML Preformatted Text
HTML preformatted text is the default method. Webulator/400 sends
preformatted text when the Tables Enabled configuration value is set to NO.
Preformatted text has the following characteristics:
•
It instructs the browser to use a fixed width font. This means that all
characters (including spaces) on the display are the same width. This
results in the characters going across a line have the same spacing as in a
traditional emulation program.
•
It produces the smallest size HTML file.
•
It is fast for the browser to render on the display.
•
The width of input fields and submit buttons are larger than the number of
characters that they hold. This means that the columns of any line that have
input fields or submit buttons do not properly line up with columns on a line
that have only output fields. The effects of this vary depending on the
composition of the display. It may range anywhere from a small nuisance to
having columns lining up with the wrong headings.
5.7.2.2 HTML Tables
Webulator/400 allows you to specify that all 5250 screen data should be included
inside of an HTML table. Webulator/400 sends HTML tables when the Tables
Enabled configuration value is set to YES.
HTML Tables have the following characteristics:
•
Tables are able to keep track on the largest number of pixels that is needed
by any column. This means that columns that have either input fields or
submit buttons have more pixels allocated to them than columns that only
have output fields. The result is that tables guarantees that all fields that
start in the same column are properly aligned but there may be extra space
between fields to compensate for the different widths of the various HTML
elements used.
•
Tables allow for the specification of a background color different from the
body of the form. This allows for reverse image attributes to be honored.
•
Tables by default use non-fixed width fonts. This makes the 5250 screen look
quite a bit different than when viewed using a traditional emulation program.
You can change the font that tables use by setting the Table Font Name
configuration entry. You may need to experiment with the font name to
ensure that all of your target browsers support it. You should be safe setting
this value to COURIER.
•
It produces much larger HTML files.
•
It is slower for the browser to render on the display.
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•
It requires a browser that supports HTML tables.
Recommendations
You are better off using preformatted text if your 5250 screens do not use
tabular data. It produces smaller files that are quicker to display and is
supported by more browsers than tables. If your programs use tabular data
and you are not satisfied with the way preformatted text aligns your columns,
experiment with tables.
5.7.3 DDS HTML Support
This section describes the DDS HTML support considerations when using
Webulator/400.
5.7.3.1 OS/400 Version Considerations
This section describes usability considerations applied for specific version of
OS/400.
V3R1/V3R6 Considerations: Browsers are context sensitive to the data stream
that they receive. In particular, they assume that all less than signs (<) are a
start of an HTML keyword and do not display any characters until it reaches the
next greater than sign (>). This causes display problems for any AS/400 data
stream that contains a < that is not an HTML keyword. Because of this,
Webulator/400 recognizes a subset of HTML keywords and escapes all <
characters (change the < to a different set of characters) that are not part of a
recognized HTML keyword. This has two sets of ramifications:
1. All < characters that are not a part of a recognized HTML keyword are
displayed properly on Webulator/400 browser displays.
2. It is possible to embed certain HTML keywords into the 5250 data stream and
have them interpreted by the browser. This means that you can include
such things as images or links to other URLs inside of your displays. Please
note that the number of supported HTML keywords is limited.
The following HTML keywords are passed to the browser intact:
<A ... > - Start of hyperlink anchor
</A> - End of hyperlink anchor
<IMG ... > - Image hyperlink
Note
Care should be taken before embedding HTML fields in your 5250 screens.
You should take into account the following constraints when designing
displays that will contain embedded HTML keywords:
208
•
You may want to make output fields that contain HTML keywords to have
a display attribute of Nondisplay (DSPATR(ND)). If you do not do this,
users viewing the display with an application other than Webulator/400
see the HTML keywords as text and not as embedded images or links.
•
HTML keywords usually require a large number of characters. You may
run into problems fitting them on your display.
•
You may run into some spacing problems. There is sometimes little to
no correlation between the amount of space needed for the keyword and
the amount of space needed for the resulting image or link.
Unleashing AS/400 Applications on the Internet
V3R2 Considerations: With the release of V3R2, IBM has introduced the HTML
DDS keyword that allows AS/400 applications to embed any HTML tag into the
5250 data steam. This method of embedding HTML offers the following
advantages:
•
HTML keywords do not occupy any display space. You can add HTML
anywhere on the display no matter how crowded it is.
•
All HTML tags are supported.
•
HTML keywords are not passed to normal ″green screens″ or emulation
programs.
Note
One limitation imposed is that HTML keywords cannot be included in subfile
records. Please refer to the following publications for more information on
the HTML DDS keyword:
•
•
AS/400 DDS Reference , SC41-3712-01
AS/400 Application Display Programming , SC41-3715-01
Webulator/400 supports the use of the DDS HTML keyword in the same way as
Workstation Gateway. Further details for the use of the DDS HTML keyword can
be found in Section 5.4.3, “DDS HTML Support” on page 187. However,
Webulator/400 has some additional configuration items that can further enhance
your application.
5.7.3.2 Emulating Color and Monochrome Displays
The Terminal Color configuration element lets you emulate either a color or
monochrome display. If you emulate a color display, Webulator/400 uses the
colors defined in the 5250 data description. If you emulate a monochrome
display, Webulator/400 displays all text in a single color and displays high
intensity characters as bold. The monochrome display configuration requires an
HTML 2.0 compliant browser to properly view Webulator/400 displays. You can
optionally define the text color by configuring the Monochrome Text Color.
Note: If you do this, you need a browser that supports extensions to HTML 2.0.
If you emulate a color display, Webulator/400 uses the colors defined in the 5250
Data Description Specifications (DDS). While this is more visually appealing, it
does require a browser that supports extensions to HTML 3.0. You can
optionally choose to define one or all of the colors by configuring the Screen
Text Colors.
5.7.3.3 HTML Headers
•
The standard Webulator/400 header contains the following HTML entries:
<HTML>
<HEAD>
<TITLE> (Text From First Output Field) </TITLE>
</HEAD>
<BODY TEXT=Monochrome Text Color
BACKGROUND=Background Image
BGCOLOR=Background Color
ONLOAD=″SetFocus()″>
•
Webulator/400 allows you to replace the standard header with either an
HTML or plain text custom header. This feature allows you to control what
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appears above the 5250 terminal data in the HTML form. For example, you
can include a link to your company′s home page or an address for sending
e-mail. If you choose to create a custom HTML header file, it must include
the following tags:
<HTML>
<HEAD>
<TITLE> (Title Text) </TITLE>
</HEAD>
<BODY (Optional BODY Attributes)>
(Optional BODY elements)
Note: All embedded file references must be qualified to the Web Server/400
document root by including a leading slash (/) in the file name. Failure to do
this may result in broken links.
Note: Webulator/400 may insert some optional BODY attributes into your
custom header based on your configuration settings. For example, if the
session has a Background Color Value configured, but the custom header
does not have a BGCOLOR attribute set, Webulator/400 inserts the proper
attribute to honor the configuration value. If the custom header has a
BGCOLOR attribute, Webulator/400 uses its value instead.
Example
The following example header places a link to a home page and a mail
address for the local WebMaster.
<HTML>
<HEAD>
<TITLE>Webulator/400 Demo</TITLE>
</HEAD>
<BODY>
<A HREF=″ / home.htm″>Home</A>
<A HREF=″mailto:[email protected]″>WebMaster</A>
<P>
•
210
If Send JavaScript is enabled, Webulator/400 automatically inserts
O N L O A D = ″SetFocus()″ into the form BODY tag. If your custom HTML
header also includes a JavaScript function that must be called on the
OnLoad event, you must include your function name in the BODY tag and a
call to the SetFocus() function at the end of your function.
Unleashing AS/400 Applications on the Internet
Example
Suppose that you have a JavaScript function called InitForm() and you
want it to be called during the OnLoad event. Your custom HTML header
should look similar to this:
<HTML>
<HEAD>
<TITLE>Webulator/400 Demo</TITLE>
</HEAD>
<BODY OnLoad=″InitForm()″>
<SCRIPT LANGUAGE = ″JAVASCRIPT″>
<!--function InitForm() {
(some JavaScript statements)
SetFocus();
return;
}
// --->
</SCRIPT>
•
If you choose to create a custom plain text header file, Webulator/400 uses
the standard Webulator/400 header followed immediately by the plain text
header in a “Preformatted” text section.
5.7.3.4 HTML Footers
•
The standard Webulator/400 header contains the </BODY> and </HTML>
entries.
•
Webulator/400 allows you to replace the standard footer with either an HTML
or plain text custom footer. This feature allows you to control what appears
below the 5250 terminal data in the HTML forms. For example, you can
include a link to your company′s home page or an address for sending
e-mail. If you choose to create a custom HTML footer file, it must include the
following tags:
(Optional BODY elements)
</BODY>
</HTML>
Note: All embedded file references must be qualified to the Web Server/400
document root by including a leading slash (/) in the file name. Failure to do
this may result in broken links.
Example
The following example footer places a link to a home page and a mail
address for the local WebMaster.
<P>
<A HREF=″ / home.htm″>Home</A>
<A HREF=″mailto:[email protected]″>WebMaster</A>
</BODY>
</HTML>
•
If you choose to create a custom plain text footer file, Webulator/400 inserts
the plain text footer in a “Preformatted” text section followed immediately by
the standard Webulator/400 footer.
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5.7.4 Additional Customization of Webulator/400
The Webulator/400 User Manual has a more detailed discussion of the following
customization/configuration items:
•
•
•
•
•
•
•
•
•
•
•
•
AS/400 terminal size
Screen background
Virtual keyboard buttons
Input field characteristics
Output characteristics
Screen text colors
Graphical menus
Converting keywords to buttons (identifying screen keywords)
Embedding HTML in the 5250 data stream
Default configuration values
Sample directory based configuration files
Webulator/400 commands
5.7.4.1 Reconfiguring Webulator/400
You may dynamically reconfigure Webulator/400 to use the latest configuration
values at any time the Web Server/400 is active by running the Set WWW
Configuration Values (SETWWWCFG) command or by setting the Update
executing RPs (UPDATE) parameter on any of the configuration commands to
*IMMED.
It is important to note that when you reconfigure the Webulator/400 settings, the
new settings take effect for all future sessions and do not change any currently
active Webulator/400 sessions. This is done as a way to prevent the
Webulator/400′s appearance and functionality from changing from one display to
another.
Note: The user profile of the person starting or reconfiguring the server must
have read access to all configuration files. The user profile of the server does
not need read access to any configuration files.
If the configuration commands are used to change the configuration, the user
that runs them must have write access to the configuration files, as well as the
temporary (*.tmp) and backup (*.bak) that are created by those commands.
5.8 Hints for Using Webulator/400
The following list describes some of the known limitations and offers possible
ways to work around them:
1. Nothing happens when the Enter key is pressed. Some browsers recognize
the Enter key and return the form data only if there is one, and only one,
input field available on the form. If there are none or multiple input fields,
the user must press the Enter submit button instead.
2. Nothing happens when a Function key is pressed. Since the browser is
handling the user input functions, it traps the Function keys for its own use
and not for Webulator/400. This means that when you press one of the
function keys (for example, F1), it either ignores you or performs a browser
function. Neither one of these is what you want. You must press the
browser submit button that corresponds to the desired Function key.
3. Columns do not line up. By default, Webulator/400 generates preformatted
text display data, which ensures that output fields line up properly.
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Unfortunately, column data does not line up if there is either an input field or
a submit button on the same line. This happens because the width of input
fields and buttons are not the same as the width of an output field. If the
columns are not lining up because of a Submit button that Webulator/400
created, you may be able to modify your keyword parsing configuration to
prevent Webulator/400 from creating the Submit button.
Note: You can have Webulator/400 generate HTML tables instead of
preformatted text. Tables guarantee that columns line up by inserting extra
space between fields. Please see Section 5.7.2.1, “HTML Preformatted Text”
on page 207 and Section 5.7.2.2, “HTML Tables” on page 207 for more
information. Please note that you must have a browser capable of displaying
tables for the display to appear.
4. No input fields have focus. Webulator/400 can generate a JavaScript routine
that automatically positions the cursor in the correct field. Please see the
JavaScript example on page 210 for more information.
Note: You must have a JavaScript capable browser for the cursor to be
positioned correctly. If you do not have Send JavaScript enabled or your
browser does not support JavaScript, you are dependent on the browser to
select an input field. Some browsers automatically select the first input field,
while several do not select any fields but instead require the user to select a
field before being able to enter data.
5. Field level prompting does not work. Webulator/400 can generate a
JavaScript routine that automatically returns to the AS/400 system the
location of the last input field that had focus. Please note that you must have
a JavaScript capable browser for the cursor position to be reported to the
AS/400 system correctly. If you do not have Send JavaScript enabled or your
browser does not support JavaScript, you must take an extra step to get field
level prompting. You can inform Webulator/400 of the field position you want
to return to the AS/400 system by typing a configurable string (the system
default is a ?) in the field and pressing a non-enter Submit button. When
Webulator/400 recognizes the Field Level Prompting string, it strips it out of
the 5250 data stream and returns the cursor location of the current field.
6. Browser does not properly display Webulator/400 displays. Various
browsers support different levels of the HTML specifications. Browsers
should ignore HTML tags that they do not understand. Unfortunately, some
browsers incorrectly interpret these unknown tags. The results can vary
from incorrect colors to improper formatting. Webulator/400 requires an
HTML 2.0 compliant browser to run most configurations and a browser that
supports HTML extensions to use some of the more advanced configuration
options.
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Browser Requirements
The following configuration elements require a browser that supports
extensions to HTML 2.0:
•
•
•
Body background color
Body background image
Monochrome terminal text color
The following configuration elements require a browser that supports
extensions to HTML 3.0:
•
•
Color terminal
Color terminal text color
The following configuration elements require a browser that supports
HTML tables:
•
•
•
Tables enabled
Table font name
Table width
The following configuration element requires a browser that supports
JavaScript:
•
Send JavaScript
You may have also included some HTML 3.0 or HTML extensions in your
custom header or footer file that may cause browser problems. Make
sure you understand the ramifications that the HTML tags may have on
older browsers before you include them in a custom header or footer file.
7. Unable to view all AS/400 output messages. Since the browser is only able
to receive data from the AS/400 system after a user submits the HTML form,
it is not possible for Webulator/400 to continually send display updates to the
browser. Webulator/400 attempts to buffer all output messages and send
them with the next display but it is not always able to do so. Webulator/400
clears all display data (seen and unseen) whenever it encounters a Clear
Unit command in the 5250 data stream. A Clear Unit command is inserted
into the 5250 data stream by various display I/O commands such as the
EXFMT command in RPG.
Note: Webulator/400 is also unable to support AS/400 break messages.
AS/400 break messages are messages that interrupt the current display and
require some sort of response (at a minimum, an Enter key) to return to the
previous display. Break messages cause Webulator/400 to be out of
synchronization with the AS/400 system and cause unpredictable results.
8. Extra displays are occasionally sent to the browser. Some host programs
send a write/read screen I/O request followed immediately by a cancel read
operation. The end result of these operations are the same as a write
request. These requests are handled seamlessly by traditional emulators
because of their constant communication link with the AS/400 system.
Webulator/400 has a little more difficulty handling these I/O requests.
Webulator/400 verifies that no Cancel requests have been generated by the
AS/400 system before sending a display to the browser. Unfortunately, there
is no guarantee that the Cancel request is received before the display is sent
to the browser. This means that certain write/read/cancel requests get past
Webulator/400′s checking and are sent to the browser. If this happens, all
you have to do is press a Virtual Keyboard button and the next display is
sent to the browser.
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Unleashing AS/400 Applications on the Internet
9. AS/400 Cursor Control Keywords are ignored. Since Webulator/400 does not
have control over how the Browser handles the user interface, the following
DDS keywords have no effect:
•
•
•
•
•
•
•
•
•
•
CSRINPONLY - Cursor Movement to Input
Capable Positions Only
FLDCSRPRG - Cursor Progression Field
HOME - Home
MOUBTN - Mouse Buttons
MSGALARM - Message Alarm
SFLCSRPRG - Subfile Cursor Progression
SFLCSRRRN - Subfile Cursor Relative Record
Number
WRDWRAP - Word Wrap
10. Unable to perform Text Assist functions. Webulator/400 is unable to fully
support programs that use the Text Assist functions (for example,
OfficeVision/400 ). Text Assist programs require more interaction with the
AS/400 system than is possible using Webulator/400.
11. The Attention button does not always work. Care should be taken before
allowing this button to be made available through Webulator/400. You must
ensure that the user profile that is signed on for a session has an Attention
program assigned to it. As long as it does, everything works fine. You can
run into problems if a Webulator/400 user presses the Attention button and
their user profile does not have an attention program defined for it. 5250
emulation programs are able to notify the AS/400 system that the Attention
key was pressed and retain control of the current display until they are
interrupted by the new attention program.
Note: If there is no attention program to run, the 5250 emulation program
continues to process the current display. Since the Web browser returns
control to the AS/400 system when any submit button is pressed (including
the Attention submit button), it must wait for a new display to arrive from the
AS/400 system before allowing the user to interact with the display. If there
is no attention program to generate a new display, the browser times out
waiting for the new display and does not allow the user to continue with the
display where the Attention button was pressed.
5.9 Other Implementation Tips
1. If you are going to make use of the HTML DDS keyword, most AS/400
programmers have never seen or used HTML. Rather than spend the hours
working out the correct syntax, it is faster to use a graphical HTML editor.
Such editors generate all of the HTML code, which you can simply cut and
paste into your AS/400 application DDS file.
2. When debugging, set the number of clients sessions such that you only have
a parent and child job. This makes finding the child job you want to debug
easier.
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5.10 HTML Gateway Comparison
The following brief list details some of the features/limitations you might want to
consider when deciding whether to use Workstation Gateway or Webulator/400:
•
The Webulator/400 has many more configuration items than Workstation
Gateway, making it easier to use for the client. A quick look at the online
documentation is available at the following URL:
http://www.inetmi.com/pubs/webulate/usrgdtoc.htm
This shows more than 20 configurable items relating to such things as:
−
−
−
−
Device capabilities
Screen appearance
Session limits
Access methods
•
When using Webulator/400 with the I/NET Commerce Server/400, secure
transactions can be made.
•
The the Netscape plugin for Webulator/400 provides correct keyboard
mappings for 5250 sessions viewed from the browser. For instance, the F12
key now provides the Cancel function (where appropriate). This enhanced
functionality is not available with Workstation Gateway.
5.11 Further Information
This section presents you with additional information about using Workstation
Gateway from IBM and/or Webulator/400 from I/NET.
5.11.1 Workstation Gateway
Workstation Gateway additional information.
5.11.1.1 Support Pages on the Internet
The support pages and FAQ for IBM′s Workstation Gateway can be found at the
following URL:
http://www.as400.ibm.com/ncc/webconn/htmlgate.htm
This is a good site especially for late breaking news and PTF information about
the Workstation Gateway, and is supported by the AS/400 team.
Another avenue for retrieving up-to-date news is Information APARs. At the time
this document was printed, 5763-TC1 Information APAR II09450 contains the
latest information. APARs can be found at the following URL:
http://as400service.rochester.ibm.com/
5.11.1.2 Code Snippets
As described elsewhere in this redbook, many business can use and are using
the Internet and Intranet capabilities of the AS/400 system. In this redbook, we
have tried to provide code snippets or examples that can be used to cut through
the tangle of the Web and enhance your applications.
The following URL offers other examples and samples of code that have made
implementing solutions simpler. These tools and techniques for untangling
some of the ″mysteries″ of the Web were created by various groups within IBM′ s
AS/400 community.
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http://as400.rochester.ibm.com/workshop/snippets/snippets.htm
It is anticipated that this site will be updated with new snippets as they become
available:
5.11.1.3 Additional Publications
Further IBM material that might be of interest:
•
•
Tips and Tools for Securing Your AS/400 , SC41-3300-00
A Guide to the Internet Connection Servers , SG24-4805-00
5.11.2 Webulator/400
Webulator/400 additional information.
5.11.2.1 Support Pages on the Internet
The Webulator/400 Frequently Asked Questions can be found at the following
URL:
http://www.inetmi.com/products/webulate/wblfaq.htm
Other support for the Webulator/400 product can be found at the following URL:
http://www.inetmi.com/products/webulate/webulate.sht
Webulator/400 users also have the opportunity to join an electronic mailing list
dedicated to discussions on Web Server/400 and Webulator/400. I/NET hosts a
customer mailing list (List Server) that allows all participants to discuss their
experiences with these products through e-mail. All messages sent to the
mailing list are automatically forwarded to the e-mail addresses of the
subscribers to the list. The sign-up page can be found at the following URL:
http://www.inetmi.com/cgi-bin/listreg
5.11.3 Additional Publications on the Web
URLs:
http://as400.rochester.ibm.com/
The AS/400 Home Page, a useful starting point
http://as400bks.rochester.ibm.com/
Contains the AS/400 Softcopy Library CD-ROMs online
http://www.developer.ibm.com/
The IBM Solution Developer Support Home Page
http://www.as400.ibm.com/nstation/infopage.htm
IBM Network Station: AS/400 Information
http://www.ncsa.uiuc.edu/General/Internet/WWW/HTMLPrimerAll.html
A Beginner′s Guide to HTML
http://www.netscape.com/comprod/mirror/client_download.html
Download Site For Netscape Navigator Products
http://www.microsoft.com/ie/download/
Download Site for Microsoft Internet Explorer 3.0
http://www.ncsa.uiuc.edu/demoweb/url-primer.html
A Beginner′s Guide to URLs
Chapter 5. HTML Gateway Implementation
217
5.12 HTML Gateway versus Other Methods
•
•
Advantages
−
Until recently, AS/400 software developers often had to learn new
languages, tools, and procedures in order to support the Web.
−
An HTML gateway allows existing AS/400 applications (whatever the
language) to be run over the Web with no code changes or conversion
programs .
−
DDS HTML keyword added allowing some display enhancements.
−
No retraining of staff who use functionally similar displays.
−
Workstation Gateway does not require HTTP server unless serving
graphics, whereas Webulator/400 has to run on top of Webserver/400.
−
Hardware can be either “green screens” or Web browsers.
Disadvantages
−
Useability
−
Performance versus CGI-bin and Net.Data
−
Security of data being transmitted
−
Synchronization of client session page with the browser display
5.13 Future Developments
This section describes how to better follow the enhancements for the
Workstation Gateway and Webulator/400 in the future.
5.13.1 Workstation Gateway
Since, the Workstation Gateway server is not really an HTTP server, many of the
foreseeable AS/400 developments will not impact the Workstation Gateway.
Secure transactions using Workstation Gateway will not be available at the same
time as secure HTTP. The best place to follow Workstation Gateway news is at
the official Web site:
http://www.as400.ibm.com/ncc/webconn/htmlgate.htm
5.13.2 Webulator/400
To keep abreast of developments of the Webulator/400 product, it is
recommended that you visit the Web site for the latest news:
http://www.inetmi.com/products/webulate/webulate.sht
5.14 Conclusions
To summarize, using a 5250-HTML gateway can give you the following benefits:
218
•
Web access to thousands of existing AS/400 applications without re-coding.
•
Existing displays can be modified to include graphics, text, and links using
the new DDS keyword ″HTML″ (displayed on Web client only).
•
Utilize existing tools and skills to develop new Web applications.
•
Clients are no longer restricted to a particular emulator or operating system.
Unleashing AS/400 Applications on the Internet
•
Complex Web applications that need to save state through a series of steps
can easily be done in DDS and 5250.
•
Ability to run AS/400 applications using Web browsers running on multiple
platforms.
Chapter 5. HTML Gateway Implementation
219
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Unleashing AS/400 Applications on the Internet
Chapter 6. Further Enhancing Your AS/400 HTML Pages
This chapter describes the use of Java Applets and JavaScripts to further
enhance your Web applications for better usability.
6.1 Java
Java is an object oriented programming language developed by Sun
Microsystems. It was originally designed for programming consumer
electronics. The language was designed to be “architecture neutral” so that it
could run on the different computer chips used in various consumer electronic
devices. But Sun soon realized that the language had the potential to become
much more.
The architecture-neutral aspect of Java makes it ideal for programming on the
Internet. It allows a user to receive software from a remote system and execute
it on a local system, regardless of the underlying hardware or operating system.
This is possible because of the interpreted nature of the language and the Java
Virtual Machine.
Traditionally, the source code of a program is written in the programming
language of choice and compiled into the machine code understood by a
particular set of computer hardware. The Java compiler, however, does not
generate machine code. Instead, it generates intermediate code called Java
bytecodes. These bytecodes are interpreted by the Java interpreter, which
executes the instructions on the particular hardware platform. The Java
interpreter and run-time system are collectively called the Java Virtual Machine
or JVM.
The bytecodes are what make Java programs portable. A program written in
Java is compiled into bytecodes. These bytecodes can be transported across a
network and executed on any system that implements a Java Virtual Machine.
6.1.1 Java Applets
An applet is a small Java program designed to be included in an HTML Web
document. The HTML document contains tags that specify the name of the Java
applet and its Uniform Resource Locator (URL). The URL is the location at which
the applet bytecodes reside on the Internet. When an HTML document
containing a Java applet tag is displayed, a Java-enabled Web browser
downloads the Java bytecodes from the Internet and uses the JVM to execute
the code from within the Web document. These Java applets are what enable
Web pages to contain animated graphics or interactive content.
Because Java applets can be downloaded from any system, security
mechanisms exist within the JVM to protect against malicious applets. The Java
run-time system verifies the bytecodes as they are downloaded from the network
to ensure they are valid bytecodes and that the code does not violate any of the
restrictions placed on Java applets by the JVM. Java applets are restricted in
what operations they can perform, how they access memory, and how they use
the JVM. The restrictions are in place to prevent a Java applet from gaining
access to underlying operating system or data on the system.
 Copyright IBM Corp. 1997
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6.1.2 Java Applications
This section describes how to implement and serve Java applications.
6.1.3 How Do I Serve Java Applets from the AS/400 System
Once you have found or written an appropriate applet, you can use it on your
site. There are three types of files available for downloading:
.java. files
These are text files that contain the source code. These are not
required if you have the .class files and do not want to modify
the code.
.class files
These are binary files that contain the compiled Java source
code (bytecodes). Each applet may require several .class files.
Other files
These are the various assorted files required to support the
applet. If you have obtained your applet from the Web, the
documentation should list these files. Make sure you download
all of them.
To serve the Java applet from your AS/400 system, you can use either FTP or
shared folders to place all of the .class and supporting files into an AS/400
directory on the IFS (Integrated File System). You need to use a directory in a
file system that supports long file names, such as the Root on the IFS. No
special directory permissions are required as long as that directory is already
configured to allow access from the Internet. The HTTP server treats the applets
the same as any other HTTP object such as .gif or .html files.
Note: You may also want to use the QOpenSys part of the IFS; this gives you the
ability to use case-sensitive names for your Java applets.
Remember
To access the IFS using FTP, you need to change to naming format ″1″. To
do this, issue the following command from your FTP client:
quote site namefmt 1
This works for Windows 95, but some clients might only need site namefmt 1.
You can now use the IFS naming convention to access the directories.
Note: For more help on how to configure and use the FTP clients and
servers on the AS/400 system, refer to TCP/IP Configuration and Reference ,
SC41-3420-04.
6.2 JavaScript
This section describes how to implement and serve JavaScripts.
JavaScript can provide logic within static HTML and also field-level validation.
Be aware that if the browser does not support JavaScript or if the feature is
disabled (the application CGI-bin), Net.Data should perform the validation.
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6.2.1 What is JavaScript?
JavaScript is an HTML scripting language that allows HTML pages to interact
with a browser. It was originally developed by Netscape as a way to extend the
functionality of HTML. It is supported by Netscape Navigator 2.0 or later and
Microsoft Internet Explorer 3.0. Various other browsers either support it or will
support it in the near future. Browsers that do not support JavaScript should
ignore the embedded JavaScript commands.
6.2.2 Webulator/400 and JavaScript
Webulator/400 can insert a small amount of JavaScript code into every HTML
page that it generates. You can enable this support by setting the Send
JavaScript configuration value.
Webulator/400 uses JavaScript to add two important usability enhancements.
The first enhancement allows the browser to insert the cursor at the start of the
correct input field on the display. It does this by calling a function during the
onLoad event. This gives the user the ability to type into a field without first
having to select it with the mouse. It also indicates to the user the first input
field that may contain an error if the row and column are properly set by the
AS/400 application. The second enhancement allows the browser to return the
row and column position of the last input field that had focus. It does this by
calling a function during the various onFocus events. This feature allows the
user to have field-level prompting without typing a question mark (?) into the
field.
6.2.3 Why Disable JavaScript?
There are a couple of reasons why you may want to disable the JavaScript
support.
1. JavaScript is an interpreted scripting language that means the browser must
perform extra work to follow the JavaScript instructions. Testing did not
indicate that performance is noticeably slower when including the JavaScript
functions. Depending on the equipment and browsers that you use, you may
see different results and determine that the added functionality is not worth
the price in performance.
2. JavaScript is relatively new and not all browsers support it. A browser
should ignore any HTML tags (including JavaScript tags) that they do not
understand. This is really why you would not want to use JavaScript in your
Web applications. Of course, there is no guarantee that all browsers act
appropriately. If your target audience uses ill-behaved browsers, you may
want to disable these features.
6.3 Further Java/JavaScript Information
URLs:.
http://ncc.hursley.ibm.com/javainfo/wp.htm
Java for AS/400 - A White Paper
http://www.ibm.com/java/
IBM Networking Computing - Java Web Site
http://ncc.hursley.ibm.com/javainfo/hurindex.html
IBM Centre for Java Technology Development
Chapter 6. Further Enhancing Your AS/400 HTML Pages
223
http://www.javasoft.com/
Sun′s Java Home page
http://www.dannyg.com/javascript/index.html
Danny Goodman′s JavaScript Pages - provides many application
excerpts
Recommended Reading:
JavaScript Bible, 2nd Edition published by IDG Books, ISBN 0-7645-3022-4.
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Chapter 7. AS/400 Internet Technology Preview
This chapter gives you a preview for the future of the AS/400 system in the
Internet world. This preview discusses some of the new implementations that
will apply to the AS/400 system in future releases.
•
AS/400 Firewall Technology
•
Internet Connection Services/400
•
SSL Support for ICCS/400
•
AS/400 HTTP Server Enhancements
•
Net.Commerce for AS/400
•
Java on the AS/400 system
7.1 AS/400 Firewall Technology
Many companies are thinking of connecting their internal corporate networks to
the Internet (and for good reason). There are potential rewards due to the
increased visibility and the possibility for new types of applications.
However, many are rightly concerned about the security of their systems. For
that reason, IBM is developing unique firewall technology that makes it easier
than ever to safely attach a network containing AS/400 systems to the Internet.
A firewall acts as a ″chokepoint″ through which all traffic to and from the Internet
flows. It prevents unwanted Internet traffic from entering your secure network,
while selectively allowing users access to the Internet. Internal users can use
browsers to access Web servers on the Internet and exchange mail with Internet
users through the firewall, while TCP/IP access from the Internet can be
selectively or entirely blocked.
7.1.1 AS/400 Firewall Benefits
•
Concentrates security administration, enforcing I/T security policy and
minimizing the opportunity for security configuration errors.
•
Provides privacy by preventing internal network information form being
accessed through the Internet.
•
Logs traffic to and from the Internet, allowing network use and misuse to be
monitored.
•
Provides flexible firewall configuration, enabling support for various security
policies. The administrator decides which services should be permitted and
which should be blocked.
7.1.2 The AS/400 Advantage
Most security experts agree that it is best to run firewall functions on a separate
processor from other system functions. In the past, that meant a separate
system had to be introduced into the network. The unique AS/400 firewall
technology is based upon an Integrated PC Server, which provides processor
separation without requiring the introduction of a new system into the network.
 Copyright IBM Corp. 1997
225
Figure 94. AS/400 Firewall Technology Preview
7.1.3 AS/400 Technology Advantages
Application programs and security programs are run on separate processor,
which eliminates the possibility of processors interfering with each other.
Compromised security programs running on the firewall cannot directly affect the
main processor.
The software and configuration information used by the firewall processor
resides on a read only disk. This eliminates the possibility of virus introduction
or modification of programs performing the communications security functions.
The main processor and firewall communicate over an internal system bus that
is not subject to ″sniffing programs″ or LANs.
The main processor can disable the firewall when tampering is detected,
regardless of the state of the firewall.
The firewall software is installed in the same manner as any other AS/400
software product. There is no need to install and configure a separate machine
and operating system as is typical with other firewalls.
Administration of the firewalls is performed by a Web browser on the internal
(secure) network. Secure sockets can be used to protect the administration
session. Authentication of the administrator is performed using the OS/400
security support so separate USERIDs or passwords are not required.
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Unleashing AS/400 Applications on the Internet
7.1.4 AS/400 Firewall Technology Components
•
•
•
•
•
•
•
•
IP packet filtering for TCP, UDP, and ICMP
SOCKS server
Proxy server for HTTP, HTTPS, FTP, and GOPHER for Web browsers
Telnet proxy
Mail relay
Split Domain Name Server (DNS)
Logging
Real-time monitoring
More AS/400 Firewall Information...
For more information on AS/400 firewall technology:
http://www.as400.ibm.com/firewall
7.2 Internet Connection Secure Server/400 (ICSS/400)
With the IBM Internet Connection Secure Server, business transactions can be
secure. The secure server is enabled when 5769-NC1 or 5769-NCE is installed.
Internet Connection Secure Server provides HTTP secure (HTTPS) transactions
with the Secure Sockets Layer (SSL) protocol. SSL is a security protocol that
was developed by NetScape Communications Corporation, along with RSA Data
Security, Inc. This protocol ensures that data transferred between a client and a
server remains private. It also allows the client to authenticate the identity of
the server.
Once your server has a digital certificate, SSL-enabled browsers such as the
NetScape Navigator can communicate securely with a server using SSL. With
SSL, a security-enabled Web site can easily be established on the Internet or on
a corporate TCP/IP network.
SSL uses a security handshake to secure the TCP/IP connection between the
client and the server. During the handshake, the client and server agree on the
security keys that they will use for the session, and the client authenticates the
server. After that, SSL is used to encrypt and decrypt the information in both the
https request and the server response, including:
•
The URL the client is requesting
•
The contents of any form being submitted
•
Access authorization information such as user names and passwords
•
All data sent between the client and the server
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227
Figure 95. Internet Connection Secure Server Preview
7.3 New Versions of HTTP
The current version of the protocol today is HTTP 1.0, but it seems that HTTP 1.1
will introduce persistent connections. A significant difference between HTTP 1.1
and earlier versions of HTTP is that persistent connections are the default
behavior of any HTTP connection. That is, unless otherwise indicated, the client
may assume that the server will maintain a persistent connection. HTTP 1.1 is
currently in the state of an Internet draft.
7.4 IBM Electronic Commerce - Net.Commerce
Net.Commerce provides a fully customizable virtual store front that allows
secure commerce to take place over the Web. Net.Commerce comes with all of
the software you need to build your first electronic store including a merchant
server that manages the storefront interface to the customer and allows
customers to browse through your catalog and place orders. The store manager
allows store personnel to keep prices and product information up to date. The
Secure Payment switch allows secure three-way credit card authorizations.
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7.4.1 What Does Net.Commerce Do?
If you have a commercial business, Net.Commerce has practical solutions for
getting you into the cyber market. Here is what Net.Commerce can do for your
business.
7.4.2 Construct a Site for Your Business
Whether your business is a small shop or a large department store, whether you
offer products or services, wholesale or retail, you can put your business on the
Web with Net.Commerce. And Net.Commerce opens opportunities for
commercial Web site developers to offer complete Web site packages to
merchants.
You can build one store or a mall that showcases several stores. Choose a
simple method of store creation and use the processes and Web pages that
come supplied with Net.Commerce, or customize your store and incorporate
legacy systems.
7.4.3 Create a Dynamic Shopping Experience
Because information about your merchandise is dynamically extracted from the
database each time a shopper views your online store, you can quickly and
easily tailor your store to changing markets and profit from emerging trends.
You can also construct shopper profiles with information you collect from your
shoppers electronically and develop and implement consumer-centered direct
marketing strategies in your online store.
A handy design tool is provided to create visually appealing displays or pages to
showcase your store and its products. You can include special effects on these
pages such as 3D graphics, animation, sound, and Java applets.
7.4.4 Manage the Shopping Process End-to-End
Net.Commerce contains task macros and application program interface (API)
functions that manage shopping tasks automatically. Shoppers register, select
products, order, and submit payment online, letting you focus on managing your
business strategy. Web pages for a shopping cart, registration form, and order
forms are supplied for your shoppers to use, and can be customized to create a
unique look and feel for your store. The supplied APIs suit many business
applications but they can also be tailored to your needs. You can even write
your own APIs for additional or unique requirements. And you can use them to
incorporate such external business applications as tax calculation and inventory
management systems into the online store you build with Net.Commerce.
Net.Commerce helps shoppers browse also. With the catalog building function,
you define the categories or departments through which shoppers navigate to
reach products, and you can lead shoppers to the same product through several
navigation routes to maximize its exposure.
Products can have different prices for promotions, sales, or shopper groups.
You define the conditions whereby these prices are valid and they are applied
automatically.
Net.Commerce is a market leader in online shipping. You decide how your
products are shipped and how to offer valued choices to consumers. You can
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use as many shipping carriers as you want, and calculate shipping charges in
ways that suit your product line such as by weight, dollar value, or quantity.
7.4.5 Help Manage Your Store
The Net.Commerce Store Manager tools make managing your store easy. You
can quickly update such information about your online store as prices or product
attributes using simple, fill-in-the-blank, on-screen forms. The information is
stored in the database and the pages your shoppers see are immediately
updated.
7.4.6 Protect Your Information and Your Shoppers
You can lock your database from unauthorized tampering and provide a
password to managers who you choose to have access. Shoppers protect their
information by providing and using a logon ID and password when they register.
User data such as credit card information is protected through Secure Sockets
Layer (SSL) encryption. IBM Net.Commerce payment for merchants provides
consumers, merchants, and financial institutions access to comprehensive,
secure credit card usage over the Internet through the Secure Electronic
Transaction (SET) protocol.
7.4.7 The IBM Net.Commerce Administrator
To build and manage an electronic store or mall, merchants use the IBM
Net.Commerce Administrator, the merchant interface component of
Net.Commerce. Merchants can easily enter store and product information and
tailor product displays to suit their merchandising requirements. Changes they
make automatically appear in the Web site of their store. And the multiple
pricing capability, sophisticated shipping features, and market identification and
targeting tools offer power and flexibility to profit from the changing marketplace
and stay ahead of the competition.
The Net.Commerce Administrator contains two data management applications,
the Site Manager and the Store Manager, and a Web page design tool called the
Template Designer.
7.4.8 Site Manager and Store Manager
Merchants use the Site Manager to create and manage the infrastructure for
their commercial Web site and the Store Manager to develop an online catalog
and manage such other information as shipping options, shopper groups, and
customer numbers. Using simple displays that look the same as fill-in-the-blank
forms, merchants enter information about the store or mall and merchandise into
the Net.Commerce database. Updating the information is quick and easy. Here
are some examples of the information that merchants can store in the database
and display on the Web pages:
230
•
The store or mall name, logo, location, contact person, contact information,
mission statement, policies, types of services and products offered, and
currency used.
•
The merchandise offered, including descriptions, product number or SKU
(stock keeping unit), images, prices, availability dates, dimensions or weight,
attributes such as size and color, and shipping methods for each product.
•
The product categories (shipping companies and services that shoppers can
select).
Unleashing AS/400 Applications on the Internet
•
Shopper groups that the merchant can define for the store.
Other information can be stored in the database for the merchant to view and
use such as:
•
Customer contact information, demographic data, shipping addresses, and a
customer number.
•
Information about the managers who have access to the store′s database.
•
Administrative information required to manage shipping, prices, and tasks
enabled through APIs.
7.4.9 Template Designer
Merchants can use the Template Designer to design Web pages. Its graphical
look, drag-and-drop capabilities, and quick testing function help to create and
test the pages. The design is laid out on a template that merchants can use to
produce as many Web pages as they want. They can create different templates
for different Web pages such as one for regular priced products and another for
products on sale. This way, related elements can be visually consistent and
unique elements visually distinct.
Merchants can create the following types of Web pages with the Template
Designer:
•
A home page for a mall or store with links to the inside.
•
A page listing product categories from which shoppers select a category to
browse.
•
A page displaying the contents of a product category from which shoppers
select a product to view in detail.
•
A page showing a product with a description, price, image, and attributes
such as color or size that shoppers can select, and a button that shoppers
click to add the product to their shopping cart.
•
Unique category and product pages for members of shopper groups.
7.5 Java for the AS/400 - A White Paper
Java is a hot, new programming language designed for today′s networked world.
This white paper discusses what Java is and why it is a key piece of the
application development strategy for the AS/400 system. Read on to find out
about Java on the AS/400 system today and where it is going in the future.
7.5.1 Java Overview
Java is an object-oriented programming language developed by Sun
Microsystems. It was originally designed for programming consumer
electronics. The language was designed to be ″architecture neutral″ so that it
could run on the different computer chips used in the various consumer
electronic devices. But Sun soon realized that the language had potential to do
much more.
The architecture-neutral aspect of Java makes it ideal for programming on the
Internet. It allows a user to receive software from a remote system and execute
it on a local system, regardless of the underlying hardware or operating system.
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This is possible because of the interpreted nature of the language and the Java
Virtual Machine.
Traditionally, the source code of a program is written in the programming
language of choice and compiled into the machine code understood by a
particular set of computer hardware. The Java compiler, however, does not
generate machine code. Instead, it generates intermediate code called Java
bytecodes. These bytecodes are interpreted by the Java interpreter, which
executes the instructions on the particular hardware platform. The Java
interpreter and run-time system are collectively called the Java Virtual Machine
or JVM.
The bytecodes are what make Java programs portable. A program written in
Java is compiled into bytecodes. These bytecodes can be transported across a
network and executed on any system that implements a Java Virtual Machine.
An applet is a small Java program designed to be included in an HTML Web
document. The HTML document contains tags that specify the name of the Java
applet and its Uniform Resource Locator (URL). The URL is the location at which
the applet bytecodes reside on the Internet. When an HTML document
containing a Java applet tag is displayed, a Java-enabled Web browser
downloads the Java bytecodes from the Internet and uses the JVM to execute
the code from within the Web document. These Java applets are what enable
Web pages to contain animated graphics or interactive content.
Because Java applets can be downloaded from any system, security
mechanisms exist within the JVM to protect against malicious applets. The Java
run-time system verifies the bytecodes as they are downloaded from the network
to ensure they are valid bytecodes and that the code does not violate any of the
restrictions placed on Java applets by the JVM. Java applets are restricted in
which operations they can perform, how they access memory, and how they use
the JVM. The restrictions are in place to prevent a Java applet from gaining
access to the underlying operating system or data on the system.
But Java can be used for more than programs running within a browser. Java is
a full-function programming language that can be used to write stand-alone
applications that run outside of a Web browser.
Java is an object-oriented language, which means the focus is on the data and
functions or methods that operate on the data. The data and the methods
comprise a class that defines the state and behavior of an object. With the
exception of a few primitive data types such as integers or floating point
numbers, everything in Java is an object. In addition to the programming
language constructs necessary for object-oriented program development, Java
includes a rich set of predefined classes that are grouped together in what are
called packages.
The Java Development Kit (JDK) version most widely available at this time is
JDK 1.0.2. This version of Java contains the following packages:
232
•
The java.lang, which contains the base classes
•
The java.util, which contains classes for commonly-used data structures
•
The java.io, which contains classes for input and output to files and streams
•
The java.net, which contains classes for sockets programming and other
networking
Unleashing AS/400 Applications on the Internet
•
The java.applet, which contains the classes needed for applet programming
•
The java.awt, which contains the classes needed for GUI development
The most recent release of Java is JDK 1.1, which contains the following
additional packages:
•
The java.text, which contains classes for internationalization that allow
applets and applications to be localized to different national languages and
conventions.
•
The java.security, which contains additional security features such as digital
signatures that allow an applet to be signed by originator and cryptography
so that information can be encrypted before traveling over the network.
•
The java.rmi, which allows objects to be distributed across the network and
called using remote method invocations.
•
The java.beans, which is a cross-platform component model used to build
applications using pluggable pieces.
•
The java.sql, which allows database access using a standard SQL interface
called JDBC (Java Database Connectivity).
Applications written using the JDK are portable. ″Write once, run anywhere″ has
become the rallying cry of Java application programmers. Java applications
developed using the integrated development environment on one system can be
deployed on a different system without having to change or recompile the code.
And Java is becoming widespread, with Java Virtual Machines available or
planned for every major hardware platform and operating system.
One of the down sides of the portable, interpreted nature of Java is performance.
While the performance of interpreted Java code is better than scripting
languages and fast enough for interactive applications, it is slower than
traditional languages whose source code is compiled directly into the machine
code for a particular machine. To improve performance, Just-In-Time compilers
(JITs) have been developed on many systems. A JIT compiler runs concurrently
with the JVM and determines which methods within the Java code are called
most often. These methods are compiled into machine code on-the-fly so that
they do not need to be interpreted each time they are encountered within a
program. Static compilers are also being developed that compile the Java
source code into machine code that is executed without interpretation. This
compilation is not done on-the-fly but is a separate step in the program
development process. And it is important to note that the machine code
generated is not portable and does not execute on other platforms.
7.5.2 Why Java for the AS/400 System?
There is a great deal of synergy between Java and the architecture of the AS/400
system. Java is an object-oriented programming language. The AS/400 system
and its predecessors have had an object-based architecture from the very
beginning. The AS/400 system knows objects!
The Java Virtual Machine and the platform independence it provides are also
well-known concepts in the AS/400 world. The AS/400 system is the only
computer system today that allows applications to move from 48-bit to 64-bit
architecture without any porting or migration effort. The AS/400 system′ s
technology independent machine interface (TIMI) has shielded AS/400 customers
from hardware technology changes for nearly 20 years.
Chapter 7. AS/400 Internet Technology Preview
233
Until now, the majority of the focus has been on client applets written in Java.
But Java is a full-function programming language that can be used to write
server applications. Java gives AS/400 developers the opportunity to move to
object-oriented programming and modernize their applications without the
complexity inherent in other object-oriented languages such as C++. Java is,
by design, simpler than C or C++. For example, Java does not implement
pointers. A Java program has a reference to an object, but that reference is not
a pointer. Java also implements automatic garbage collection, which eliminates
the memory leaks that cause ″out-of-memory″ errors in C and C++ code today.
Other complex features of C++ that make the language both difficult to learn
and to debug do not exist in Java. These include multiple inheritance,
templates, and operator overloading. This makes Java a much simpler language
and shortens both the learning curve and the development cycle when compared
to other object-oriented languages.
For the AS/400 customer who does not want to write programs in Java, the
bytecode portability ensures that ″100% Pure Java″ code will run without
recompilation on the AS/400 system. This means that any application
development environment can be used to develop the code and create the Java
bytecodes. The application can be deployed on any platform that includes a
JVM that conforms to the Sun specifications.
For large IT departments, this means that a ″one-size-fits-all″ approach can be
used for application deployment. Only one version of a Java program is needed,
regardless of how many different computer platforms are supported within the
organization.
Java is an open, cross-platform, de facto industry standard language. It solves
Web programming problems that are difficult to solve with more traditional
languages. It is the ideal language for network computing (thin clients) and the
World Wide Web. The AS/400 system is on its way to becoming the premiere
server for network computing. Java is an important piece of the overall AS/400
Internet/intranet strategy.
7.5.3 Java on the AS/400 System Today
A technology preview of Java on the AS/400 system is available today. This
preview is a port of Sun′s JDK 1.0.2 to the AS/400 system. The java.awt
windowing classes are not currently included in this preview. The JDK 1.0.2
currently runs on top of OS/400 and is not integrated into the operating system.
Because it is not optimized for the AS/400 system and does not include any JIT
or other compiler technology, the performance characteristics are similar to the
initial Java offering from Sun when they first released the technology. For many
applications, the performance of the technology preview is slower than what is
seen on comparable platforms using JIT or other optimizing technology.
The technology preview is not intended for application deployment. But because
Java can be written on any platform and deployed on any other platform, the
preview can be used to run programs written on other platforms without
modification or recompilation. The true portability of Java is highlighted as the
code moves from any platform and executes without change on the AS/400
system.
Java applications can also be written on client workstations today that access
AS/400 programs and data. There are a number of different options available to
do this. Client applets or applications can use:
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•
JDBC to access AS/400 database
•
The java.net sockets to access server applications on the AS/400 system
•
Native methods to call out to other client/server access services
At this time, many of these options entail writing middleware to connect to the
AS/400 system. Java client extensions will be available in the future that can be
used to access AS/400 programs and data from a Java applet or application on
the client.
For information on other object-oriented or network computing options available
for the AS/400 system today, visit the AS/400 Partners In Development Web
page.
7.5.3.1 Strategy and Direction for Java on the AS/400 System
Java is a key application development language for the AS/400 system. As the
Java technology evolves from Sun, the AS/400 system will take advantage of the
new functions and features of the language.
There is an exciting future for Java on the AS/400 system. This section
describes the current plans for Java technology, but is not a commitment to the
function or performance of future products on the AS/400 system. This document
will be updated as these plans change in the future.
Currently an effort is underway to integrate Java technology with OS/400. A
Java Virtual Machine that resides below the TIMI is planned to enable fast
interpretation and execution of Java code on the AS/400 system. In addition, a
direct execution static compiler is being developed that can generate RISC
machine code as well as the portable Java bytecodes. This will allow Java code
to directly execute on the AS/400 system without the overhead of interpretation.
High-performance garbage collection is also being developed for the AS/400
system to improve both the performance and the scalability of Java. The high
level of integration and tuning of Java on the AS/400 system will meet the
objective of competitive performance while preserving cross-platform portability.
Other technology is being developed that will allow GUI applications to run on
the AS/400 system without modification. Support is planned for Java on the
AS/400 system that intercepts GUI requests coming from a Java program and
reroutes the requests to an attached workstation running its own JVM. The
workstation can interpret and display the java.awt graphical components. This
allows AS/400 programs to have graphical interfaces using the standard Java
language on the AS/400 system.
In addition, plans include integration of other Java packages with OS/400
components for both ease-of-use and improved performance. All of the
integration and performance work is being done ″under-the-covers″ of OS/400
without compromising portability of the Java code.
Some AS/400-specific classes are also planned that are not part of the JDK itself,
but are supplied as a convenience to programmers who want to access more
traditional AS/400 application environments from Java. These classes provide
access to unique AS/400 features such as data queues, record-level database
I/O, and traditional programming languages such as CL and RPG.
The unique single-level-store architecture is also being exploited to give Java
objects on the AS/400 system an advantage not available on any other platform.
Chapter 7. AS/400 Internet Technology Preview
235
Java objects on the AS/400 system will be full-fledged system objects allowing
them to be persistent, shared, secure, backed up, and restored. This allows the
AS/400 system to offer persistent Java objects with performance and support
that is unparalleled in the industry. The AS/400 single-level-store technology
permits Java objects to be stored in their object form without the performance
and maintenance overhead of two-level-store operating systems.
The AS/400 system is uniquely positioned to leverage Java as it evolves from its
current Web focus to a full commercial application environment. The strengths
of the AS/400 system are combined with Java′s object-oriented, network
computing technology to provide solutions for the new millennium.
7.5.4 Summary
Java is the language of choice for programming in today′s network computing
environment. It allows true portability of applications between platforms without
modification or recompilation. It is an open, cross-platform, industry standard
that is being supported by all of the major players in the computer industry
today.
Java is available now for the AS/400 system. And the best is yet to come...
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Chapter 8. Internet Application Performance
8.1 Internet Application Performance Overview
This chapter gives you an overview of what is important to select the right
system and model for the applications serving the Internet. Also, it gives some
configuration recommendations to optimize and tune the system for optimal
Performance.
8.1.1 How Fast Can a Web Site Go?
You want to know how to design your Web site to get maximum speed. And you
are probably thinking in terms of how many hits per day your Web server can
handle. For example, ″Our www.askas400.com site needs to service 1 million
hits per day.″
But wait! If you base your choices only on how many hits your Web server can
serve per day, you may end up buying less equipment than you need.
8.1.2 How Many Connections per Second is Enough?
A hit and a connection are the same thing. Throughout our information, we use
the maximum connections per second as a gauge, but how many seconds are in
a day?
24 hours * 60 minutes per hour * 60 seconds per minute = 86,400 seconds
1 million hits per day = 1 000 000 / 86 400=11.6 connections per second
But are the requests to your site evenly distributed over 24 hours every day? In
reality, most Web sites have peaks and valleys in the rate of requests. When
doing capacity planning, you need to concentrate on planning for the peaks.
Otherwise, you over estimate the maximum capacity of your Web site.
 Copyright IBM Corp. 1997
237
Figure 96. Distribution of Connections
This graph shows the importance of understanding the peaks in your Web
request rate. To read the chart, first find the line that most closely matches your
Web site:
Do 60% of your requests occur in only four hours of a day, for example, from
6PM to 10PM Eastern Standard Time? Do 90% of your requests occur in eight
hours of a day, for example, 8AM to noon and 1PM to 5PM?
Do virtually all of your requests occur in 12 hours of a day, for example, 8AM
Eastern Standard Time to 5PM Pacific Standard Time? Or does the worldwide
appeal of your site result in a request load that is balanced around the clock?
Once you have found the line that most closely matches your Web site request
load, find on the X-axis the number of millions of hits per day for your Web site.
Finally, find the corresponding value on the Y-axis, which tells you the number of
connections per second your Web site needs to support in order to achieve the
corresponding number of hits per day.
For example, let′s assume that www.askas400.com needs to service 3.5 million
hits per day. If you assume that the request rate is balanced throughout 24
hours a day, www.askas400.com needs to be configured to support 40
connections per second. However, the staff at www.askas400.com knows that
80% of their requests arrive in the same eight-hour period every day. Based on
the graph, you can see that to service this peak request rate, www.askas400.com
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needs to be configured to support nearly 100 connections per second, resulting
in dramatically different hardware requirements!
You also need to take file size into consideration when thinking about connection
rates. A hit can mean anything ranging from a quick sub-second browse
request, all the way to the minutes (and computer resource) required for
streaming audio or video. As a result, you should use Web benchmark numbers
for relative sizing only. Even the popular WebStone benchmarking only covers
GET transactions, not POST transactions, which are used with forms and CGI
programs. This next graph shows why you need to consider both file size and
the peak hit rate when planning your Web site requirements.
We took the maximum connection rate for a sample network design and created
a chart showing the maximum hits per day expected based on file size and the
peak hit rate, or hit distribution. In this example, when the average file size is
5KB, if the hit distribution means 60% of the hits occur in four hours, this
configuration will support 2.1 million hits per day. However, if the connections
are evenly distributed over 12 hours, the same configuration supports 3.7 million
per day. Similarly, if the file size were 10KB and the hit distribution means 60%
of the hits occur in four hours, this configuration supports 1.8 million hits per
day; but if 80% of the connections occur in eight hours, 2.7 million hits per day
can be supported.
So, which is it? 1.8 million, 2.1 million, 2.7 million, or 3.7 million per day? If you
do not know the average file size or the peak hit rate, you cannot understand the
maximum capacity of your Web site.
If you want to see a comparison of how different file sizes affect the response
time, see Figure 100 on page 246.
8.2 Internet Connection Performance for AS/400 System
Performance information for the Internet Connection for AS/400 (IC/400) product
is included in this section. There are many factors that can impact overall
performance (for example, end-user response time and throughput) in the
complex Internet environment, some of which are included in the following list:
•
Web Browser
−
−
−
•
Communications network
−
−
−
•
Processing speed of the client system
Performance characteristics of the Web browser
Client application performance characteristics
Speed of the communications links
Capacity of any proxy servers
Congestion of network resources
AS/400 WWW (Web) server
−
−
−
−
AS/400 processor speed
Utilization of key AS/400 resources (CPU, IOP, memory, disk)
Web server performance characteristics
Application performance characteristics
Chapter 8. Internet Application Performance
239
The primary focus of this section is to discuss the performance characteristics of
the AS/400 system as a server in a Web serving environment, providing capacity
planning information and recommendations for best performance.
Data accesses across the Internet differ distinctly from accesses across
″traditional″ communications networks. The additional resources to support
Internet transactions by the CPU, IOP, and line are significant and must be
considered in capacity planning. Typically, in a traditional network:
•
•
•
Request and response (between client and server).
Connections/sessions are maintained between transactions.
Networks are tuned to use large frames.
For Internet transactions, there are a dozen or more line transmissions
(including acknowledgements) per transaction:
•
•
•
•
•
•
A connection is established between client and server.
Requests and responses (between client and server).
The connection is closed.
Networks typically have small frame (MTU) sizes.
HTML displays to browser contain more bytes than traditional.
One user transaction may contain several separate Internet transactions.
The information that follows is based on performance measurements and
analysis done in the AS/400 division laboratory. The highlights, general
conclusions, and recommendations are included. Results listed here do not
represent any particular customer environment. Actual performance may vary
significantly from what is provided here.
8.3 AS/400 Commercial Processing Workload (CPW)
The Commercial Processing Workload is a modified version of the TPC-C
(Transaction Processing Performance Council) workload, which is an industry
standard for measuring performance. CPW results represent the performance
of many sophisticated commercial environments. By using CPW, IBM can more
accurately represent our customers′ more robust commercial workloads.
Note
CPW results do not only represent the performance of IBM (or another
vendor′s models), they represent the performance of many sophisticated
commercial environments. By using CPW, you can more accurately
benchmark the performance of the AS/400 system against that of other
similar systems.
8.3.1 AS/400 Advanced Server Models V3R7
The following chart shows the relative Performance Characteristics of all AS/400
Advanced Server Models running with the current version of OS/400 V3R7.
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Figure 97. AS/400 Relative Performance - CPW for Advanced Server Models V3R7
As you can see on the preceding chart, the Performance Capability of the server
models go over a wide range. It starts at about 30 CPW for the smallest of the
40S Models, over 80 CPW of the 50S, to the fastest model 53S showing more
than 500 CPW.
The CPW Value is useful in determining the system performance growth
provided by different AS/400 models in the Internet environment. As a first
approximation, CPW values can be used when a quick estimate is required,
followed by a more detailed analysis using BEST/1 for OS/400.
For example, a model 40S-2109 has a CPW value of 27 and the fastest 40S-2112
has a CPW value of 87. So based on the previous assumption, we can say that a
40S-2112 may provide about three times the throughput of a 40S-2109.
The ability of a system to process a unit of work is made up of many factors.
The most important factors are CPU speed and DASD access time. It is
important to note that changing the CPU only affects the CPU component of the
workload. If you know the CPU component for a particular workload, you can
estimate an improvement in the CPU component by using the Relative
Performance Rating.
Note
The preceding method does not take into account wait time for queues in the
system for CPU, DASD, or other system components that are a function of
utilization, and cannot easily be modeled by hand. Capacity planning should
be done with a capacity planning tool such as BEST/1 for OS/400.
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241
8.4 Web Serving with the HTTP Server
The Hypertext Transfer Protocol (HTTP server) allows AS/400 systems attached
to a TCP/IP network to provide objects to any Web browser. At a high level, the
connection is made, the request is received and processed, a file system is
accessed (or a CGI program is accessed), the data is sent to the browser, and
the connection is ended. The HTTP server jobs and the communications router
tasks are the primary jobs/tasks involved (there is not a separate user job for
each attached user).
8.4.1 Web Serving Performance Measurements
The following charts provide a summary of the measured performance data.
Results listed here do not represent any particular customer environment.
Actual performance may vary significantly from what is provided here.
8.4.2 AS/400 HTTP Server Performance
Figure 98. AS/400 HTTP versus CGI-Bin versus Net.Data
8.5 Web Serving Performance Recommendations
Throughput for Web serving is typically discussed in terms of the number of
hits/second (connections/second and transactions/second mean the same).
Typically, the CPU is the resource that limits capacity. If a large AS/400 model is
used with a single IOP, the IOP may the limiting factor.
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Note
For more detailed information regarding specific AS/400 model Web serving
capacity, see your IBM Representative.
8.5.1 CISC versus RISC
The HTTP serving environment on RISC AS/400 models provides better
performance (per CPW) than on CISC AS/400 models. The hits/sec/CPW factor
for RISC models is almost twice that of the CISC models. This is due to the
better RISC technology for C-language environments and to recent performance
improvements to TCP/IP and IC/400.
Note
Note that CPWs (relative system performance metrics) are derived from a
commercial workload′s capacity. Therefore, relative capacity ratios for Web
serving may not track accordingly. However, they should be adequate for a
high-level capacity planning exercise.
8.5.2 Response Time (General)
User response time is made up of Web browser (client work station) time,
network time, and server time. The response times in measurements taken on
the AS/400 system do not include Web browser time; they typically contribute 0.5
seconds to 2 seconds to response time. A problem in any one of these areas
may cause a significant performance problem for an end user. To an end user,
it may seem apparent that any performance problem is attributed to the server,
even though the problem is elsewhere.
It is common for pages that are being served to have imbedded images (gifs).
Each of these separate Internet transactions adds to the response time as they
are serially retrieved from various servers (some browsers can concurrently
retrieve two URLs).
8.5.3 HTTP and TCP/IP Configuration Tips
1. The number of HTTP server jobs (CHGHTTPA command) controls the
minimum and maximum number of HTTP server jobs handling HTTP
requests. The reason for having multiple server jobs is that when one server
is waiting for a disk or communications I/O to complete, a different server
job can process another user′s request. Also, for N-way systems, each CPU
may simultaneously process server jobs. The system adjusts the number of
servers that are needed automatically (within the bounds of the minimum
and maximum parameters).
The smallest minimum allowed is two (one parent and one child server).
Typically three to five servers are adequate for smaller systems (50 CPWs or
less). For larger systems (more than 50 CPWs) dedicated to HTTP serving,
increasing the number of servers to 10 or more may provide better
performance. Also, if CGI or Net.Data is used (which are more disk I/O
intensive), configuring more servers may provide better performance. Try
not to have more than what is needed as this may cause unnecessary
system activity.
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243
2. The maximum frame size parameter (MAXFRAME on LIND) can be increased
from 1994 bytes for TRLAN (or other values for other protocols) to its
maximum of 16 393 to allow for larger transmissions. Typically documents
are larger than 1994 bytes.
3. The maximum transmission unit (MTU) size parameter (CFGTCP command)
for both the route and interface affect the actual size of the line flows.
Increasing these values from 576 bytes to a larger size (up to 16 388)
probably reduces the overall number of transmissions, and therefore,
increases the potential capacity of the CPU and the IOP.
Similar parameters also exist on the Web browser. The negotiated value is
the minimum of the server and browser (and perhaps any bridges/routers)
so increase them all.
4. Increasing the TCP/IP buffer size (TCPRCVBUF and TCPSNDBUF on the
CHGTCPA command) from 8K bytes to 64K bytes may increase the
performance when sending larger amounts of data.
5. Error and Access Logging: Having logging turned on causes a small amount
of system overhead (CPU time, extra I/O). Turn logging off for best capacity.
Use the WRKHTTPCFG command to make these changes.
6. Name Server Accesses: For each Internet transaction, the server accesses
the name server for information (IP address and name translations). These
accesses cause significant overhead (CPU time, comm I/O) and greatly
reduce system capacity. These accesses can be eliminated by using the
WRKHTTPCFG command and adding the line ″DNSLookUp Off″. For V3R7,
PTF SF35478 is a prerequisite for this change.
8.5.4 HTTP Server Memory Requirements
Follow the faulting threshold guidelines suggested in the Work Management
Guide by observing/adjusting the memory in both the machine pool and the pool
that the HTTP servers run in.
From one benchmark measured in the lab, (simple HTTP page serving with 1K
byte files), the memory requirement for the HTTP server pool is:
1000 K bytes + 400 K bytes for each HTTP server
Factors that may significantly increase the memory requirements include using
larger document sizes, using CGI-Bin programs, and using Net.Data.
8.5.5 AS/400 Model Selection
Use the information provided in this section along with the characterization of
your HTTP workload environment in a capacity planning exercise (perhaps with
BEST/1) to choose the appropriate AS/400 model. All the tasks associated with
HTTP serving are ″non-interactive″, so AS/400 server models probably provide
the best price/performance.
8.5.6 File System Considerations
Web serving performance varies significantly based on which file system is used.
Each file system has different overhead and performance characteristics. Note
in Figure 99 on page 245 that serving from the ROOT or QOPENSYS directories
provide the best system capacity. If Web page development is done from
another directory, consider copying the data to a higher-performing file system
for production use.
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8.5.6.1 AS/400 HTTP Server Performance, Simple Page Serving
Figure 99. AS/400 HTTP Server Performance, Simple Page Serving
8.5.7 File Size Considerations
Note in Figure 100 on page 246 that serving larger files uses more system
resources. The connect and disconnect costs are similar regardless of size, but
cost for the transmission of the data with TCP/IP and the IFS access vary with
size. As file size increases, the IOP is more efficient by being able to achieve a
higher aggregate data rate. However, being larger, the files require more data
frames, thus causing the hits/sec capacity for the IOP to go down accordingly.
Chapter 8. Internet Application Performance
245
Figure 100. AS/400 File Size Variation
8.5.8 Communications/LAN IOPs
Since there are a dozen or more line flows per transaction, the Web serving
environment utilizes the IOP more than other communications environments.
Use the performance monitor (STRPFRMON) and the component report
(PRTCPTRPT) to measure IOP utilization. Attempt to keep the average IOP
utilization at 60% or less for best performance.
Use the data in Figure 100 to estimate 2619 TRLAN IOP capacity (2617 Ethernet
IOP capacities are similar). IOP capacity depends on file size and MTU size
(make sure you increase the maximum MTU size parameter).
On larger AS/400 models, the comm/LAN IOP may become the bottleneck before
the CPU does. If additional HTTP capacity is needed, multiple IOPs (with unique
IP addresses) can be configured. The overall workload must be ″manually″
balanced by Web browsers requesting documents from a set of interfaces. The
load can also be balanced across multiple IP addresses by using a distributed
name server.
8.6 Net.Data and DB2WWW
246
•
Since Net.Data is the follow-on to DB2WWW version 1, ensure that you have
the right PTFs applied to get the new version. See
http://www.as400.ibm.com/netdata for the latest code levels and more
product information.
•
Net.Data performs significantly better than DB2WWW version 1. Note from
the data in Figure 99 on page 245 that the relative capacity improved by
more than a factor of two.
Unleashing AS/400 Applications on the Internet
•
Net.Data is more disk I/O intensive than typical HTTP transactions.
Therefore, more HTTP server jobs may be needed to provide the optimal
level of system throughput.
•
A Net.Data SQL macro is slightly slower than an SQL CGI-Bin. This is
because the SQL macro does some formatting while the SQL CGI-Bin does
not do any formatting. There are functional advantages in using an SQL
macro.
−
−
−
Direct reuse of existing SQL statements (no programming required).
Provides the built-in ability to format SQL results.
Provides the ability to store SQL results in a table and pass. the results
to a different language environment (for example, REXX).
•
A Net.Data HTML macro is slightly better than an HTML CGI-Bin because of
the implementation of activation groups.
•
If macro performance is critical, turn off the reporting function (uses more
CPU time).
•
For REXX macros, calling an external REXX program performs better than
inline REXX statements.
8.7 5250/HTML Workstation Gateway
5250/HTML Workstation Gateway enables all Web browsers to be clients to
existing 5250 applications without making changes to the application. At a high
level, the connection is made, the request is received and processed, the user
job processes the application, the workstation I/O is converted from 5250 to
HTML, the HTML is sent to the browser, and the connection is ended. The tasks
involved are the Workstation Gateway server jobs, the user job (one per client),
the communications router tasks, the virtual terminal task, and the Telnet task.
Figure 101. 5250/HTML Workstation Gateway Comparison
Chapter 8. Internet Application Performance
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8.7.1 Workstation Gateway Performance Recommendations
This section describes specific WSG performance recommendations.
8.7.1.1 Workstation Gateway CPU Time and Capacity
Workstation Gateway involves a significant amount of CPU processing compared
with other workstation connectivity types (for example, Telnet). Typical
commercial transactions with Workstation Gateway use three times the CPU time
of Telnet running the same application (on the target system). Therefore, it is
recommended to use Workstation Gateway casually or for non-performance
critical transactions. It is not a good price/performance decision to convert all of
the workstations in an existing production environment from twinax or
communications to Workstation Gateway. (Note that Workstation Gateway uses
six times the CPU time of Telnet in CISC models, but only three times more CPU
time in RISC models.)
8.7.1.2 Workstation Gateway Response Time
Response time is made up of browser time, network time, and server time.
Browsers typically contribute 0.5 seconds to 2 seconds to response time,
network time can vary widely, and AS/400 server time typically ranges from 0.2
seconds to 5 seconds depending on the model, load, and application.
A problem in any one of these areas can cause a significant performance
problem for an end user. To an end user, it may seem apparent that any
performance problem is attributed to the server even though the problem is
elsewhere.
Better response time may be achieved by using the STYLE button on the
browser (Workstation Gateway window) to remove the F-keys on the bottom.
This reduces the browser time to process and show the display.
8.7.1.3 Workstation Gateway Configuration
Default settings for the Workstation Gateway related parameters typically work
well. Changing some of the following parameters may improve performance:
•
The number of clients per Workstation Gateway server job (CHGWSGA
command): This parameter controls the maximum number of users that can
be attached to a given Workstation Gateway server job. When the
Workstation Gateway server is started, several server jobs start. As clients
sign on, they are assigned to these server jobs (one server is assigned to its
maximum before users are assigned to the next server).
It is unlikely that this parameter needs to be changed. Increasing this
parameter may be recommended if there are hundreds of casual users.
Decreasing this parameter may be recommended if there are just several
heavy users.
248
•
MAXFRAME (on LIND): The maximum frame size parameter can be
increased from 1994 bytes for TRLAN (or other values for other protocols) to
its maximum of 16 393 to allow for larger transmissions.
•
MTU size (CFGTCP command): The maximum transmission unit size
parameter for both the route and interface effect the actual size of the line
flows. Changing these values from 576 bytes to a larger size (perhaps the
maximum of 16 388) may reduce the overall number of transmissions. This
needs to be considered on both the server and the Web browser. Typically,
even simple displays have several thousand bytes of HTML data.
Unleashing AS/400 Applications on the Internet
8.7.1.4 Workstation Gateway Memory Requirements
Follow the faulting threshold guidelines suggested in the Work Management
Guide by adjusting the memory in the machine pool (the pool that the
Workstation Gateway servers run in) and the pool that the user jobs run in (use
the WRKSYSSTS command). For the Workstation Gateway server pool, the
actual memory required per server (working set size) varies significantly by the
workstation I/O characteristics of the workload. From one benchmark measured
in the lab, the memory requirement for the Workstation Gateway server pool is:
600 K bytes + 700 K bytes for each WSG server
8.7.1.5 Communications Lines and IOPs
Workstation Gateway/HTML sends significantly more bytes to the client
workstation than Telnet does for the same application. Therefore, plan for
additional communications line capacity to handle this extra load. For example,
a Telnet transaction may consist of 1K bytes, while a Workstation Gateway
transaction may be 6K bytes for the same transaction.
8.7.1.6 AS/400 Model Selection
Use the information provided here along with the characterization of your
Workstation Gateway workload environment in a capacity planning exercise
(perhaps with BEST/1).
Server models may not be the best choice for Workstation Gateway
environments. The user job is labeled as an ″interactive″ job, while the other
tasks involved (Workstation Gateway servers and communications tasks) all are
tagged ″non-interactive″. For a typical commercial transaction with Workstation
Gateway, the ″interactive″ portion of the transaction is about 20% of the total
transaction′s CPU time. To avoid decreasing the effectiveness of your server
model when using Workstation Gateway, it is recommended that you keep the
″interactive″ portion of your overall CPU utilization below the threshold at where
the efficiency drops off.
•
•
Do not do heavy applications through Workstation Gateway.
Limit Workstation Gateway to casual use (low number of Workstation
Gateway transactions).
Otherwise, use traditional (non-server) AS/400 models.
8.8 Net.Data Performance, Hints, and Tips?
Reference
For more detailed performance information and tips and techniques to
improve performance, see Chapter 4, “Net.Data Implementation” on
page 111.
8.9 CGI-Bin Performance, Hints, and Tips
Reference
For more detailed performance information and tips and techniques to
improve performance, see Chapter 3, “Common Gateway Interface (CGI-BIN)
Implementation” on page 57.
Chapter 8. Internet Application Performance
249
8.10 Workstation Gateway, Hints, and Tips
Reference
For more detailed performance information and tips and techniques to
improve performance, see Chapter 5, “HTML Gateway Implementation” on
page 169.
250
Unleashing AS/400 Applications on the Internet
Appendix A. ILE RPG and ILE COBOL Sample CGI Programs
Disclamer!
The source code for the Cobol and RPG program are included for reference.
A.1 ILE RPG Sample CGI Program CUSTINFO
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
***************************************************************
*
* Program:
Prompt user for mailing info and response
*
* Language:
ILE RPG
*
* Description: This program is used to process an HTML Form
*
as input and add a record to a database
*
It is a SAMPLE program
*
* APIs Used:
QtmhRdStin - Read from Standard Input. This
*
API is used to read the input
*
Data from the user.
*
*
QtmhCvtDb - Convert to DB. This API takes
*
the Stdin input and converts it
*
into a group data structure that
*
can be processed by an RPG pgm.
*
The field names in the DDS must
*
match the names in the HTML Form
*
*
QtmhWrStout - Write to Standard Output. This
*
API writes the output to the user.
*
The Output Must be in the correct
*
HTML format and it MUST have a
*
MIME Header.
*
*
QCMDEXC
- Execute a CL Command from within a
*
High Level Langauge Program.
*
Used to Override the output
*
database file.
*
* 1. COMPILE THIS SOURCE MEMBER AS MODULE CUSTINQRP (PDM OPTION=15)
*
* 2. CREATE PROGRAM CUSTINQRP FROM MODULE CUSTINQRP (PDM OPTION=26)
*
WITH PROMPT (PF4) AND BNDSRVPGM(QTCP/QTMHCGI)
*
* Refer to the TCP/IP Configuration manual for API Parms
*
***************************************************************
* DEFINE YOUR FILES HERE
**********************************************************************
FCUSTPF
UF A E
DISK
USROPN
**********************************************************************
* DS contains the name of the file and library used by the CVTDB API *
**********************************************************************
dDBFILE
DS
d
10
inz(′ CUSTPF′ )
d
10
inz(′ WEBDB′ )
***************************************************************
* Buffer used to convert the string data into fields
*
***************************************************************
DDBBuff
E DS
EXTNAME(CUSTPF)
 Copyright IBM Corp. 1997
251
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
*******************************************************************
* Standalone Fields Used for PARMS and work fields in the Program *
*******************************************************************
DINBuff
S
2048
DINBuffLn
S
9B 0
DINActLn
S
9B 0
DDBRecLn
S
9B 0
DDBCvtLn
S
9B 0
DRspCode
S
9B 0
DOutLn
S
9B 0
DCmdLen
S
15P 5
DEMAILM
C
′ We Will Contact you via E-Mail′
DSMAILM
C
′ We Will Contact you via Surface +
d
Mail′
DPMAILM
C
′ We Will Contact you via Phone′
***************************************************************
* Buffer used for standard API Error handling
*
* Copied from QSYSINC/QRPGLESRC - QUSEC
*
***************************************************************
DQUSEC
DS
D*
Qus EC
D QUSBPRV
1
4B 0
D*
Bytes Provided
D QUSBAVL
5
8B 0 inz(16)
D*
Bytes Available
D QUSEI
9
15
D*
Exception Id
D QUSERVED
16
16
***************************************************************
* This DS contains a Standard startup needed for HTML
*
*
This is used as output to the user. You should change
*
*
the text between the <title> text </title> tags.
*
*
*
*===>
Hex 15 (x′ 1 5 ′ ) is the newline character and is
*
*===>
REQUIRED between lines of output
*
*===>
A Line of output may not exceed 120 Characters
*
***************************************************************
dStdHdr
DS
d
23
inz(′ Content-type: text/html′ )
d
2
inz(x′1515′)
d
6
inz(′ < HTML>′ )
d
1
inz(x′ 1 5 ′ )
d
6
inz(′ < head>′ )
d
1
inz(x′ 1 5 ′ )
d
7
inz(′ < title>′ )
d
1
inz(x′ 1 5 ′ )
d
24
inz(′ Thank you for your input′ )
d
8
inz(′ < / title>′ )
d
1
inz(x′ 1 5 ′ )
d
6
inz(′ < body>′ )
d
1
inz(x′ 1 5 ′ )
d
4
inz(′ < hr>′ )
d
1
inz(x′ 1 5 ′ )
***************************************************************
* This DS contains a Standard trailer needed for HTML
*
*
This is used as output to the user.
*
***************************************************************
dStdTrl
DS
d
7
inz(′ < / body>′ )
d
1
inz(x′ 1 5 ′ )
d
7
inz(′ < / html>′ )
d
1
inz(x′ 1 5 ′ )
252
Unleashing AS/400 Applications on the Internet
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
***************************************************************
* This DS contains the user output data. It should change
*
* from program to program.
*
***************************************************************
dOutInf
DS
d
6
inz(′ Name: ′ )
dnameo
like(Name)
d
4
inz(′ < BR>′ )
d
1
inz(x′ 1 5 ′ )
d
7
inz(′ Addr1: ′ )
daddr1o
like(addr1)
d
4
inz(′ < BR>′ )
d
1
inz(x′ 1 5 ′ )
d
7
inz(′ Addr2: ′ )
daddr2o
like(addr2)
d
4
inz(′ < BR>′ )
d
1
inz(x′ 1 5 ′ )
d
6
inz(′ City: ′ )
dcityo
like(city)
d
1
inz(′ ′ )
dstateo
like(state)
d
1
inz(′ ′ )
dzipo
like(zip)
d
1
inz(′ -′ )
dzipp4o
like(zipp4)
d
4
inz(′ < BR>′ )
d
1
inz(x′ 1 5 ′ )
d
8
inz(′ Phone: (′ )
dphaco
like(phac)
d
2
inz(′ ) ′ )
dphpreo
like(phpre)
d
1
inz(′ -′ )
dphnumo
like(phnum)
d
5
inz(′ Ext ′ )
dphexto
like(phext)
d
4
inz(′ < BR>′ )
d
1
inz(x′ 1 5 ′ )
d
7
inz(′ EMail: ′ )
deaddro
like(eaddr)
d
4
inz(′ < BR>′ )
d
1
inz(x′ 1 5 ′ )
***************************************************************
* This DS contains the user output message. It should change *
* from program to program.
*
***************************************************************
dOutMsg
DS
d
4
inz(′ < hr>′ )
domsg
40
d
4
inz(′ < BR>′ )
d
1
inz(x′ 1 5 ′ )
dOVRCMD
DS
d
20
inz(′ OVRDBF FILE(CUSTPF) ′ )
d
21
inz(′ TOFILE(WEBDB/CUSTPF) ′ )
d
12
inz(′ MBR(*FIRST) ′ )
d
14
inz(′ OVRSCOPE(*JOB)′ )
dDLTOVR
DS
d
20
inz(′ DLTOVR FILE(CUSTPF) ′ )
d
9
inz(′ LVL(*JOB)′ )
Appendix A. ILE RPG and ILE COBOL Sample CGI Programs
253
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
***************************************************************
*
*
* Set length of input buffer. Call the API to get input
*
* from Standard Input. The string will have the field names
*
* and values. This is used for the POST Method. The number
*
* of bytes received is set in the field WSR-LEN-RECEIVED.
*
*
*
* Refer to the TCP/IP Configuration manual for API Parms
*
*
*
***************************************************************
c
MOVE
*blanks
INBuff
c
EVAL
INBuffLn = %SIZE(INBuff)
c
CALLB
′ QtmhRdStin′
c
Parm
INBuff
c
Parm
INBuffLn
c
Parm
INActLn
c
Parm
QUSEC
***************************************************************
*
*
* Set length of Database Buffer then call the convert to
*
* Database Function. This takes the string of variable names *
* and values and maps them to field names like a normal read *
* from a screen.
*
*
*
* Refer to the TCP/IP Configuration manual for API Parms
*
*
*
***************************************************************
c
EVAL
DBRecLn = %SIZE(DBBuff)
c
CALLB
′ QtmhCvtDb′
c
Parm
DBFILE
c
Parm
INBuff
c
Parm
INActLn
c
Parm
DBBuff
c
Parm
DBRecLn
c
Parm
DBCvtLn
c
Parm
RspCode
c
Parm
QUSEC
***************************************************************
* Setup the output message based on the mail selection.
*
* MOVE the input data to the output buffer to format it.
*
***************************************************************
c
SELECT
c
when
MAIL = ′ E′
c
MOVEL (P) EMAILM
omsg
c
when
MAIL = ′ S′
c
MOVEL (P) SMAILM
omsg
c
when
MAIL = ′ P′
c
MOVEL (P) PMAILM
omsg
c
ENDSL
254
Unleashing AS/400 Applications on the Internet
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
c
MOVEL
NAME
NAMEo
c
MOVEL
ADDR1
ADDR1o
c
MOVEL
ADDR2
ADDR2o
c
MOVEL
CITY
CITYo
c
MOVEL
STATE
STATEo
c
MOVEL
ZIP
ZIPo
c
MOVEL
ZIPP4
ZIPP4o
c
MOVEL
PHAC
PHACo
c
MOVEL
PHPRE
PHPREo
c
MOVEL
PHNUM
PHNUMo
c
MOVEL
PHEXT
PHEXTo
c
MOVEL
EADDR
EADDRo
***************************************************************
* Write the data to the user. Write the standard header,
*
*
the user data, and the standard trailer.
*
***************************************************************
c
EVAL
OutLn = %SIZE(StdHdr)
c
CALLB
′ QtmhWrStout′
c
Parm
StdHdr
c
Parm
OutLn
c
Parm
QUSEC
c
EVAL
OutLn = %SIZE(OutInf)
c
CALLB
′ QtmhWrStout′
c
Parm
OutInf
c
Parm
OutLn
c
Parm
QUSEC
c
EVAL
OutLn = %SIZE(OutMsg)
c
CALLB
′ QtmhWrStout′
c
Parm
OutMsg
c
Parm
OutLn
c
Parm
QUSEC
c
EVAL
OutLn = %SIZE(StdTrl)
c
CALLB
′ QtmhWrStout′
c
Parm
StdTrl
c
Parm
OutLn
c
Parm
QUSEC
***************************************************************
*
*
* Point to the Database file in the WEBDB Library.
*
* Open the database file
*
* Write the data that the user entered to the Database File
*
* Close the database file
*
* Delete the Override
*
*
*
***************************************************************
c
EVAL
CmdLen = %SIZE(OVRCMD)
c
CALL
′ QCMDEXC′
c
Parm
OVRCMD
c
Parm
CmdLen
c
OPEN
CUSTPF
c
WRITE
custrec
c
CLOSE
CUSTPF
c
EVAL
CmdLen = %SIZE(DLTOVR)
c
CALL
′ QCMDEXC′
c
Parm
DLTOVR
c
Parm
CmdLen
c
seton
lr
Appendix A. ILE RPG and ILE COBOL Sample CGI Programs
255
A.2 ILE Cobol Sample CGI Program CUSTINFO
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
PROCESS APOST NOMONOPRC
IDENTIFICATION DIVISION.
*
* NOMONOPRC is required so that the called procedure names are
* not changed to UPPERCASE.
*
***************************************************************
*
* Program:
Prompt user for mailing info and response
*
* Language:
ILE Cobol
*
* Description: This program is used to process an HTML Form
*
as input and add a record to a database
*
It is a SAMPLE program
*
* APIs Used:
QtmhRdStin - Read from Standard Input. This
*
API is used to read the input
*
Data from the user.
*
*
QtmhCvtDb
- Convert to DB. This API takes
*
the Stdin input and converts it
*
into a group data structure that
*
can be processed by a cobol pgm.
*
The field names in the DDS must
*
match the names in the HTML Form
*
*
QtmhWrStout - Write to Standard Output. This
*
API writes the output to the user.
*
The Output Must be in the correct
*
HTML format and it MUST have a
*
MIME Header.
*
*
QCMDEXC
- Execute a CL Command from within a
*
High Level Langauge Program.
*
Used to Override the output
*
database file.
*
*
After the MODULE is created a CRTPGM command is required
*
to build the program. You must include the Service
*
Program QTMHCGI from the library QTCP
*
***************************************************************
PROGRAM-ID. CUSTINFOCB.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
SOURCE-COMPUTER. IBM-AS400.
OBJECT-COMPUTER. IBM-AS400.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT CUSTINF ASSIGN TO DATABASE-CUSTPF
ORGANIZATION IS sequential
ACCESS IS sequential
FILE STATUS IS custinf-stat.
DATA DIVISION.
FILE SECTION.
FD custinf.
01 custinf-record.
COPY DDS-custrec OF custpf.
256
Unleashing AS/400 Applications on the Internet
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
*
WORKING-STORAGE SECTION.
77 WS-CMD-LEN
PIC S9(10)v9(5) comp.
77 CUSTINF-STAT
pic xx.
77 WSR-STDIN-DATA
PIC X(32768).
77 WSR-LEN-REQ
PIC S9(9) BINARY.
77 WSR-LEN-CVTD
PIC S9(9) BINARY.
77 WSR-RSP-CODE
PIC S9(9) BINARY.
77 WSR-LEN-RECEIVED
PIC S9(9) BINARY.
77 WSR-LEN-OUT
PIC S9(9) BINARY.
77 WSR-LEN-BUFF
PIC S9(9) BINARY.
01 ws-ovrdbf-cmd.
05
pic x(53) value
′ OVRDBF FILE(CUSTPF) TOFILE(WEBDB/CUSTPF) MBR(*FIRST)′ .
05
pic x(15) value
′ OVRSCOPE(*JOB)′ .
01 ws-dltovr-cmd.
05
pic x(53) value
′ DLTOVR FILE(CUSTPF) LVL(*JOB)′ .
01 WSR-DB-NAME.
05 ws-db-name
pic x(10) value ′ CUSTPF′ .
05 ws-lib-name
pic x(10) value ′ WEBDB′ .
***************************************************************
* Buffer used to convert the string data into fields
*
***************************************************************
01 CUST-BUFF.
COPY DDS-CUSTREC of custpf.
COPY QUSEC OF QSYSINC-QLBLSRC.
***************************************************************
* This group contains a Standard startup needed for HTML
*
*
This is used as output to the user. You should change
*
*
the text between the <title> text </title> tags.
*
*
*
*===>
Hex 15 (x′ 1 5 ′ ) is the newline character and is
*
*===>
REQUIRED between lines of output
*
***************************************************************
01 WS-STANDARD-HEADER.
05
PIC X(23) VALUE ′ Content-type: text/html′ .
05
PIC XX
VALUE X′ 1 5 1 5 ′ .
05
pic x(6) value ′ < HTML>′ .
05
pic x
value x′ 1 5 ′ .
05
pic x(6) value ′ < HEAD>′ .
05
pic x
value x′ 1 5 ′ .
05
pic x(7) value ′ < Title>′ .
05
pic x(24) value ′ Thank you for your input′ .
05
pic x(8) value ′ < / Title>′ .
05
pic x
value x′ 1 5 ′ .
05
pic x(7) value ′ < / HEAD>′ .
05
pic x
value x′ 1 5 ′ .
05
pic x(6) value ′ < Body>′ .
05
pic x
value x′ 1 5 ′ .
05
pic x(4) value ′ < hr>′ .
05
pic x
value x′ 1 5 ′ .
Appendix A. ILE RPG and ILE COBOL Sample CGI Programs
257
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
***************************************************************
* This group contains a Standard trailer needed for HTML
*
*
This is used as output to the user.
*
***************************************************************
01 WS-STANDARD-TRAILER.
05
pic x(7) value ′ < / Body>′ .
05
pic x
value x′ 1 5 ′ .
05
pic x(7) value ′ < / html>′ .
05
pic x
value x′ 1 5 ′ .
***************************************************************
* This group contains the user output data. It should change *
* from program to program.
*
***************************************************************
01 ws-output-info.
05
pic x(6) value ′ Name: ′ .
05 name
like name of cust-buff.
05
pic x(4) value ′ < br>′ .
05
pic x value x′ 1 5 ′ .
05
pic x(7) value ′ addr1: ′ .
05 addr1
like addr1 of cust-buff.
05
pic x(4) value ′ < br>′ .
05
pic x value x′ 1 5 ′ .
05
pic x(7) value ′ addr2: ′ .
05 addr2
like addr2 of cust-buff.
05
pic x(4) value ′ < br>′ .
05
pic x value x′ 1 5 ′ .
05
pic x(6) value ′ City: ′ .
05 city
like city of cust-buff.
05
pic x value space.
05 State
like state of cust-buff.
05
pic x value space.
05 zip
like zip of cust-buff.
05
pic x value space.
05 zipp4
like zipp4 of cust-buff.
05
pic x(4) value ′ < br>′ .
05
pic x value x′ 1 5 ′ .
05
pic x(7) value ′ Phone: ′ .
05
pic x value ′ ( ′ .
05 phac
like phac of cust-buff.
05
pic xx value ′ ) ′ .
05 phpre
like phpre of cust-buff.
05
pic x value ′ -′ .
05 phnum
like phnum of cust-buff.
05
pic x(6) value ′ Ext ′ .
05 phext
like phext of cust-buff.
05
pic x(4) value ′ < br>′ .
05
pic x value x′ 1 5 ′ .
05
pic x(6) value ′ Email ′ .
05 eaddr
like eaddr of cust-buff.
05
pic x(4) value ′ < br>′ .
05
pic x value x′ 1 5 ′ .
01 ws-output-message.
05
pic x(4) value ′ < hr>′ .
05 ws-message
pic x(40) value spaces.
05
pic x(4) value ′ < br>′ .
05
pic x value x′ 1 5 ′ .
*
LINKAGE SECTION.
258
Unleashing AS/400 Applications on the Internet
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
*
* Beginning of mainline
*
PROCEDURE DIVISION.
MAIN-LINE.
MOVE LENGTH OF QUS-EC TO BYTES-PROVIDED OF QUS-EC.
***************************************************************
*
*
* Set length of input buffer. Call the API to get input
*
* from Standard Input. The string will have the field names
*
* and values. This is used for the POST Method. The number
*
* of bytes received is set in the field WSR-LEN-RECEIVED.
*
*
*
* Refer to the TCP/IP Configuration manual for API Parms
*
*
*
***************************************************************
MOVE length of WSR-STDIN-DATA to wsr-len-req.
CALL procedure ′ QtmhRdStin′ USING WSR-STDIN-DATA
WSR-LEN-REQ
WSR-LEN-RECEIVED
QUS-EC.
***************************************************************
*
*
* Set length of Database Buffer then call the convert to
*
* Database Function. This takes the string of variable names *
* and values and maps them to field names like a normal read *
* from a screen.
*
*
*
* Refer to the TCP/IP Configuration manual for API Parms
*
*
*
***************************************************************
MOVE length of CUST-BUFF to WSR-LEN-BUFF.
Call procedure ′ QtmhCvtDb′ using WSR-DB-NAME
WSR-STDIN-DATA
WSR-LEN-RECEIVED
CUST-BUFF
WSR-LEN-BUFF
WSR-LEN-CVTD
WSR-RSP-CODE
QUS-EC.
***************************************************************
* Write the data to the user. Write the standard header,
*
*
the user data, and the standard trailer.
*
***************************************************************
MOVE LENGTH OF WS-STANDARD-HEADER TO WSR-LEN-OUT.
CALL procedure ′ QtmhWrStout′ USING WS-STANDARD-HEADER
WSR-LEN-OUT
QUS-EC.
MOVE corr custrec of cust-buff to ws-output-info.
MOVE LENGTH OF WS-output-info
TO WSR-LEN-OUT.
CALL procedure ′ QtmhWrStout′ USING WS-output-info
WSR-LEN-OUT
QUS-EC.
Appendix A. ILE RPG and ILE COBOL Sample CGI Programs
259
|---+----1----+----2----+----3----+----4----+----5----+----6----+----7----|
Evaluate mail of cust-buff
when ′ E′
move ′ We will contact you via E-mail′ to ws-message
when ′ S′
move ′ We will contact you via Surface Mail′ to
ws-message
when ′ P′
move ′ We will contact you via phone′ to ws-message
end-evaluate.
MOVE LENGTH OF WS-output-message TO WSR-LEN-OUT.
CALL procedure ′ QtmhWrStout′ USING WS-output-message
WSR-LEN-OUT
QUS-EC.
MOVE LENGTH OF WS-STANDARD-TRAILER TO WSR-LEN-OUT.
CALL procedure ′ QtmhWrStout′ USING WS-STANDARD-TRAILER
WSR-LEN-OUT
QUS-EC.
***************************************************************
*
*
* Point to the Database file in the WEBDB Library.
*
* Open the database file
*
* Write the data that the user entered to the Database File
*
* Close the database file
*
* Delete the Override
*
*
*
***************************************************************
MOVE LENGTH OF ws-ovrdbf-cmd to ws-cmd-len.
CALL ′ QCMDEXC′ using ws-ovrdbf-cmd ws-cmd-len.
OPEN extend custinf.
MOVE cust-buff to custinf-record.
write custinf-record.
Close custinf.
MOVE LENGTH OF ws-dltovr-cmd to ws-cmd-len.
call ′ QCMDEXC′ using ws-dltovr-cmd ws-cmd-len.
EXIT-DONE.
GOBACK.
260
Unleashing AS/400 Applications on the Internet
A.3 HTML Input Form for CUSTINFO
<HTML>
<HEAD>
<title>Get Customer Feedback</title>
</head>
<body>
<FORM METHOD=″post″
action=″ / cgi-bin/custinfo.pgm″>
<h1>Customer Information/Satisfaction Survey</h1><br>
<hr>
Name <INPUT type=″text″ name=″name″ SIZE=″30″><br>
Address1 <INPUT type=″text″ name=″addr1″ SIZE=″30″><br>
Address2 <INPUT type=″text″ name=″addr2″ SIZE=″30″><br>
City <INPUT type=″text″ name=″city″ SIZE=″25″><br>
State <INPUT type=″text″ name=″state″ SIZE=″2″>
Zip <Input type=″text″ name=″zip″ size=″5″>
- <Input type=″text″ name=″zipp4″ size=″4″><br>
Phone ( <input type=″text″ name=″phac″ size=″3″>)
<input type=″text″ name=″phpre″ size=″3″> <input type=″text″ name=″phnum″ size=″4″>
Ext <input type=″text″ name=″phext″ size=″4″><br>
E-Mail Address: <input type=″text″ name=″eaddr″ size=″45><br>
I would like to correspond via
•<input type=″radio″ name=″mail″ Value=″E″ Checked>E-Mail“
•<input type=″radio″ name=″mail″ Value=″S″>Surface Mail“
•<input type=″radio″ name=″mail″ Value=″P″ >Phone Call“
<hr>
If you have used our service in the past please complete the following form.<br>
How satisfied are you with our service to date?<br>
<sl>
<li><input type=″radio″ name=″sat″ value=″1″> Very Satisfied
<li><input type=″radio″ name=″sat″ value=″2″> Satisfied
<li><input type=″radio″ name=″sat″ value=″3″> Neither Satisfied nor Dissa
<li><input type=″radio″ name=″sat″ value=″4″> Dissatisfied
<li><input type=″radio″ name=″sat″ value=″5″> Very Dissatisfied
<li><input type=″radio″ name=″sat″ value=″6″ Checked> I have not used you
</sl>
<br><input type=″submit″ value=″Enter″><br>
</FORM>
</body>
</html>
Appendix A. ILE RPG and ILE COBOL Sample CGI Programs
261
A.4 DDS for the CUSTPF file
-----A----------T-Name++++++RLen++TDpB------Functions++++++++++++++++++
R CUSTREC
NAME
30
ADDR1
30
ADDR2
30
CITY
25
STATE
2
ZIP
5
ZIPP4
4
PHAC
3
PHPRE
3
PHNUM
4
PHEXT
4
EADDR
45
MAIL
1
SAT
1
262
Unleashing AS/400 Applications on the Internet
Appendix B. HTML Gateway Code Examples
This appendix discusses sample codes you might want to try and use when developing AS/400 Internet
applications using the HTML gateway.
B.1 HTML Field Overlap Examples
The following examples show where the HTML appears when you use the following coding:
Example 1
The HTML field has a starting column 2 before an output field. The HTML appears before the field:
A 01
A 01
FLD1A
20
O 15 7DFTVAL(′ Output Field′ )
15 5HTML(′<p>HTML code′ )
and results in:
HTML code
Output Field
Example 2
The HTML field has a starting column 1 before an output field, meaning that the HTML starts at the
attribute byte of the output field. The HTML appears before the field:
A 01
A 01
FLD1A
20
O 15 6DFTVAL(′ Output Field′ )
15 5HTML(′<p>HTML code′ )
and results in:
HTML code
Output Field
Example 3
The HTML field has a starting column equal to an output field. The HTML appears before the first
character of the field:
A 01
A 01
FLD1A
20
O 15 6DFTVAL(′ Output Field′ )
15 6HTML(′<p>HTML code′ )
and results in:
HTML code Output Field
Example 4
The HTML field has a starting column 1 past the starting column of an output field. The HTML appears
after the first character of the output field:
A 01
A 01
FLD1A
20
O 15 6DFTVAL(′ Output Field′ )
15 7HTML(′<p>HTML code′ )
and results in:
OHTML codeutput Field
Example 5
 Copyright IBM Corp. 1997
263
The HTML field has a starting column 1 past the ending column of an output field, meaning that it
overlaps the ending attribute. The HTML appears after the last character of the output field:
A 01
A 01
FLD1A
20
O 15 6DFTVAL(′ Output Field′ )
15 27HTML(′<p>HTML code′ )
and results in:
Output FieldHTML code
Example 6
The HTML field has a starting column 2 past the ending column of an output field. The HTML appears
after the output field:
A 01
A 01
FLD1A
20
O 15 6DFTVAL(′ Output Field′ )
15 28HTML(′<p>HTML code′ )
and results in:
Output Field
HTML code
Notes:
1. Merging HTML and DDS fields does not occur for input fields. Merging occurs only for output
fields.
2. HTML tags are inserted into the data stream if the device query indicates that the device is an
AS/400 5250 Workstation Gateway virtual terminal. Otherwise, for normal displays, the HTML tags
are ignored.
264
Unleashing AS/400 Applications on the Internet
B.2 Logon Exit Code Examples for Workstation Gateway
This section shows some sample codes for Logon Exit function implementation.
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
Module Description *************************************************/
*/
*/
Source File Name: exitpgm.c
*/
*/
Module Name: Workstation Gateway Server logon exit program.
*/
*/
Service Program Name: n/a
*/
*/
Source File Description:
*/
*/
This module contains functions to allow a client browser to
*/
bypass an AS/400 sign-on panel and invoke an application.
*/
*/
Reference:
*/
TCP/IP Configuration and Reference SC41-3420 Appendix-I.
*/
*/
End Module Description *********************************************/
#define _EXITPGM_C
/**********************************************************************/
/* All file scoped includes go here
*/
/**********************************************************************/
#ifndef __stdio_h
#include <stdio.h>
#endif
#ifndef __string_h
#include <string.h>
#endif
#ifndef __stdlib_h
#include <stdlib.h>
#endif
/**********************************************************************/
/* All file scoped Constants go here
*/
/**********************************************************************/
#define
#define
#define
#define
SIZE
FNAME
FWIDTH
BLANK
10
21
240
′ ′
/* Qualified database file name size */
/* Width of one database file record */
/**********************************************************************/
/* All file scoped type declarations go here
*/
/**********************************************************************/
/* Structure for data passed to Server Logon exit program.
*/
/**********************************************************************/
Figure 102 (Part 1 of 7). Sample Exit Program for HTML Gateway
Appendix B. HTML Gateway Code Examples
265
typedef struct
{
char *OperSpecInfo_p;
int Lgth_OperSpecInfo;
char ClientIPaddr[15];
int CCSID;
char AllowOper[1];
char UserProfile[SIZE];
char Password[SIZE];
char ProgramLib[SIZE];
char ProgramName[SIZE];
char InitialMenu[SIZE];
} QAPP0100_I_t;
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
Operation Specific Info
(Input) */
Operation Spec Info length (Input) */
Client IP Addr.
(Input) */
CCSID of operation info
(Input) */
Allow Operation ′ 0 ′ = N,′ 1 ′ = Y(Output)*/
User Profile.
(Output) */
Password.
(Output) */
Library of program to run.(Output) */
Program to invoke.
(Output) */
Initial menu to invoke. (Output) */
/**********************************************************************/
/* All file scoped Macro invocations go here
*/
/**********************************************************************/
/**********************************************************************/
/*
*/
/* Macro name: TRACE
*/
/*
*/
/* Log test result entry to an output file for workstation gateway. */
/*
*/
/* Arguments:
x - Text string of application-specific
*/
/*
trace data from the calling program. */
/*
y - Test results output file pointer.
*/
/*
*/
/**********************************************************************/
#define TRACE(x, y)
{
memset(file_buff, BLANK, sizeof(file_buff));
sprintf(file_buff, ″%s%c″ , x, ′ \0′ ) ;
fwrite(file_buff, FWIDTH, 1, y);
}
\
\
\
\
\
/**********************************************************************/
/* All internal function prototypes go here
*/
/**********************************************************************/
static void exitpgm
(char *,int,char *,int,char *,char *,char *,char *,char *,char *);
static void WriteParms
(char *,int,char *,int,char *,char *,char *,char *,char *,char *);
/**********************************************************************/
/* All file scoped variable declarations go here
*/
/**********************************************************************/
char file_name[FNAME];
FILE *test_file;
char file_buff[FWIDTH];
/* Output results database file name
*/
/* Output results database file pointer */
/* Output results file buffer
*/
Figure 102 (Part 2 of 7). Sample Exit Program for HTML Gateway
266
Unleashing AS/400 Applications on the Internet
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
Function Specification *********************************************/
*/
Function Name: Main
*/
*/
Descriptive Name: Application Logon exit program sample program. */
*/
This test exit program provides control over signon panels via */
the WSG server in the V3R2 release.
*/
*/
Notes: For V3R2 the ″argv[]″ parameters are ″char *″ by definition.*/
Reference integers as ″*(int(argv[1]))″ , for example.
*/
Consider the method for passing them back to the caller. */
*/
Dependencies:
*/
WSG Application Logon exit point QIBM_QTMT_WSG format QAPP0100*/
was registered during WSG V3R2 installation.
*/
*/
Restrictions:
*/
*/
None
*/
*/
Messages:
*/
*/
None
*/
*/
Side Effects:
*/
*/
None
*/
*/
Functions/Macros called:
*/
*/
TRACE - Write one data record to test results file.
*/
*/
Input:
*/
chat * argv[1]
- Operation specific information
*/
int
argv[2]
- Length of operation specific information */
char * argv[3]
- IP address of the remote host system.
*/
int
argv[4]
- CCSID of the operation specific info
*/
char * argv[5]
- Allow operation ′ 0 ′ = No, ′ 1 ′ = Yes(output) */
char * argv[6]
- User profile to be used (output)
*/
char * argv[7]
- Password to be used (output)
*/
char * argv[8]
- Program library to be used (output)
*/
char * argv[9]
- Program name to be used (output)
*/
char * argv[10]
- Menu panel to be used (output)
*/
*/
Exit Normal: Return AllowOper value to server application.
*/
*/
Exit Error: None
*/
*/
End Function Specification *****************************************/
void main(int argc, char *argv[])
{
exitpgm(argv[1],
*((int *)(argv[2])),
argv[3],
*((int *)(argv[4])),
argv[5],
argv[6],
argv[7],
argv[8],
argv[9],
argv[10]);
return;
}
/* End main */
Figure 102 (Part 3 of 7). Sample Exit Program for HTML Gateway
Appendix B. HTML Gateway Code Examples
267
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
Function Specification *********************************************/
*/
Function Name: exitpgm
*/
*/
Descriptive Name: Workstation Gateway Server (WSG) Logon exit.
*/
*/
This test exit program provides control over user authentication */
to a workstation gateway in the V3R2 release.
*/
*/
Notes:
*/
*/
Dependencies:
*/
*/
Workstation Gateway Logon exit point QIBM_QTMT_WSG was
*/
registered during WEB V3R2 installation.
*/
*/
Restrictions:
*/
*/
None
*/
*/
Messages:
*/
*/
None
*/
*/
Side Effects:
*/
*/
None
*/
*/
Functions/Macros called:
*/
*/
None
*/
*/
Input:
*/
char * OperSpecInfo_p
- Operation Specific Information.
*/
int
Lgth_OperSpecInfo - Length (in bytes) of Operation
*/
Specific Information.
*/
char ClientIPaddr
- Client Internet Protocol Address.
*/
int
CCSID
- CCSID of operation info
*/
*/
Output:
*/
char * AllowOper
- Allow Operation (′0′ = Reject),
*/
(′1′ = Accept).
*/
char * UserProfile
- User Profile to be used for sign on. */
char * Password
- Password to be used for sign on.
*/
char * ProgramLib
- Library of program to invoke.
*/
char * ProgramName
- Name of program to invoke.
*/
char * InitialMenu
- Initial menu to invoke.
*/
*/
Exit Normal: (See OUTPUT)
*/
*/
Exit Error: None
*/
*/
End Function Specification *****************************************/
static void exitpgm(char *OperSpecInfo_p,
int Lgth_OperSpecInfo,
char ClientIPaddr[15],
int CCSID,
char AllowOper[1],
char UserProfile[SIZE],
char Password[SIZE],
char ProgramLib[SIZE],
char ProgramName[SIZE],
char InitialMenu[SIZE])
{
/* Entry point */
/* exitpgm start from here */
Figure 102 (Part 4 of 7). Sample Exit Program for HTML Gateway
268
Unleashing AS/400 Applications on the Internet
/********************************************************************/
/*
*/
/* You can design your own logical flow here to check if user is
*/
/* authorized to bypass sign on screen. Following are some examples.*/
/*
*/
/* (1) Validate Client IP address.
*/
/* (2) Parse the ″OperSpecInfo_p″ input string.
*/
/*
*/
/* Then
*/
/* Return AllowOper of ′ 0 ′ - Reject this clients request.
*/
/* Return AllowOper of ′ 1 ′ - Accept this clients request.
*/
/* Set related return values for client browser.
*/
/*
*/
/********************************************************************/
/*
*/
/****** Be sure to modify below for your environment **************/
/*
*/
/* Following is an example by checking client IP address.
*/
/*
*/
/* Accept the following IP address for AS/400 sign-on bypass.
*/
/*
*/
/*
9.5.100.110 /9.5.100.111 / 9.5.100.112
*/
/*
*/
/* Then assign the user id, password and program name, program
*/
/* library.
*/
/*
*/
/********************************************************************/
/* change here for your logical */
char Accept_IP[] = ″9.5.100.110
9.5.100.111
9.5.100.112
″;
if (strstr(Accept_IP, ClientIPaddr)) {
memcpy(UserProfile, ″JOENORMAL ″ , SIZE);
memcpy(Password,
″JOENORMAL ″ , SIZE);
memcpy(ProgramLib, ″ITSOIC400 ″ , SIZE);
memcpy(ProgramName, ″SHTMLR
″ , SIZE);
memcpy(InitialMenu, ″
″ , SIZE);
memcpy(AllowOper, ″1″,
1);
} else {
memcpy(AllowOper, ″0″,
1);
}
/********************************************************************/
/* Call function to write input parameters as received to file.
*/
/********************************************************************/
WriteParms(OperSpecInfo_p,
Lgth_OperSpecInfo,
ClientIPaddr,
CCSID,
AllowOper,
UserProfile,
Password,
ProgramLib,
ProgramName,
InitialMenu);
return;
}
/* End program exitpgm.c
*/
/* end of exitpgm */
Figure 102 (Part 5 of 7). Sample Exit Program for HTML Gateway
Appendix B. HTML Gateway Code Examples
269
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
Function Specification *********************************************/
*/
Function Name: WriteParms
*/
*/
Descriptive Name: Write the input parameters as received to file. */
*/
*/
Notes:
*/
*/
Dependencies:
*/
None
*/
*/
Restrictions:
*/
None
*/
*/
Messages:
*/
None
*/
*/
Side Effects:
*/
None
*/
*/
Functions/Macros called:
*/
*/
system
*/
sprintf
*/
TRACE - Write one data record to test results file.
*/
*/
Input:
*/
char * OperSpecInfo_p
- Operation Specific Information.
*/
int
Lgth_OperSpecInfo - Length (in bytes) of Operation
*/
Specific Information.
*/
char * ClientIPaddr
- Client Internet Protocol Address.
*/
int
CCSID
- CCSID of operation information
*/
char * AllowOper
- Allow Operation (′0′ = Reject),
*/
(′1′ = Accept).
*/
char * UserProfile
- User Profile to be used for sign on. */
char * Password
- Password to be used for sign on.
*/
char * ProgramLib
- Library of program to invoke.
*/
char * ProgramName
- Name of program to invoke.
*/
char * InitialMenu
- Initial menu to invoke.
*/
*/
Output:
*/
A single, serial data record written to the test results file. */
*/
Exit Normal: (See OUTPUT)
*/
*/
Exit Error: None.
*/
*/
End Function Specification *****************************************/
static void WriteParms(char *OperSpecInfo_p,
int Lgth_OperSpecInfo,
char ClientIPaddr[15],
int CCSID,
char AllowOper[1],
char UserProfile[SIZE],
char Password[SIZE],
char ProgramLib[SIZE],
char ProgramName[SIZE],
char InitialMenu[SIZE])
/* Entry point */
{
Figure 102 (Part 6 of 7). Sample Exit Program for HTML Gateway
270
Unleashing AS/400 Applications on the Internet
/********************************************************************/
/* Local Variables
*/
/********************************************************************/
char loc_buff[FWIDTH];
/* Local TRACE buffer */
/********************************************************************/
/* Create a database file to write the logon attempt results to.
*/
/********************************************************************/
system(″QSYS/CRTPF FILE(QUSRSYS/EXITPGM) RCDLEN(240) SIZE(*NOMAX)″ ) ;
/********************************************************************/
/* Build up the qualified database file name.
*/
/********************************************************************/
sprintf(file_name, ″%s″, ″QUSRSYS/EXITPGM″ ) ;
/********************************************************************/
/* Open database file for permanent log of test results.
*/
/* mode = a(ppend) b(inary) 128-byte fixed-length records
*/
/********************************************************************/
test_file = fopen(file_name,″ab, lrecl=240, type=record, recfm=f″ ) ;
/********************************************************************/
/* Build up the input record for the test results database file
*/
/* Write parameters that were passed in to the output file:
*/
/********************************************************************/
sprintf(loc_buff,
″IP: %s CCSID: %d Allow: ′%c′ Profile: %s Password: %s ″
″Library: %s Program: %s Menu: %s OperLen: %d Oper: >%s<″ ,
ClientIPaddr,
CCSID,
*AllowOper,
UserProfile,
Password,
ProgramLib,
ProgramName,
InitialMenu,
Lgth_OperSpecInfo,
OperSpecInfo_p);
TRACE(loc_buff, test_file);
fclose(test_file);
return;
}
#undef _EXITPGM_C
Figure 102 (Part 7 of 7). Sample Exit Program for HTML Gateway
Appendix B. HTML Gateway Code Examples
271
A live version of the following code can be seen in action on the AS/400 Web Technology page by
going to:
http:/www.as400.ibm.com/internetdemo
Then go to the 5250 section, Ship Status (the third icon down in the lefthand frame).
*****************************************************************
* PROGRAM NAME
: ORDSTAT
* PROGRAM DESCRIPTION : This program will request an order number
*
and if it is in file, will then display
*
order status. If it is not, will
*
display an error message.
*
* COMPILATION
: To compile this program, use the
*
standard CRTRPGPGM command.
*
*
* PROGRAMMER
:
* DATE
: 07/15/96
*****************************************************************
FCUSMSTP IF E
K
DISK
FCUSFMT CF E
WORKSTN
C
*IN15
DOWEQ′ 0 ′
*
* Overlay order not found (CUSPMT) if error (IN99)
C
*IN99
CASEQ′ 0 ′
HEADNG
C
END
C
EXFMTCUSPMT
*
* If not end, and valid order number (444), display status
C
*IN15
IFEQ ′ 0 ′
C
ORD
CHAINCUSREC
99
C
*IN99
IFEQ ′ 0 ′
C
EXFMTCUSFLDS
C
ENDIF
C
ENDIF
C
ENDDO
C
MOVE ′ 1 ′
*INLR
* Subroutine to display title and PF key line
C
HEADNG
BEGSR
C
WRITECUSFTG
C
WRITECUSHDG
C
ENDSR
272
Unleashing AS/400 Applications on the Internet
A*************
A* FILE NAME
A* FILE DESCRIPTION
A* DATE
A*********
A*
A
R CUSREC
A*
A
ORD
A
A
NAME
A
A
STAT
A
A
K ORD
: CUSMSTP
: Customer Master File
: 07/15/96
5
20
10
ORD must be unique
TEXT(′ Order number′ )
COLHDG(′ Order′ ′ Number′ )
TEXT(′ Customer Name′ )
COLHDG(′ Customer′ ′ Name′ )
TEXT(′ Status ′ )
COLHDG(′ Status′ )
Appendix B. HTML Gateway Code Examples
273
A*%%TS SD 19960716 130224 MARIAN
REL-V3R1M0 5763-PW1
A*************************************************************
A* FILE NAME: CUSFMT
A* DESCRIPTION: DISPLAY FILE FOR ENTERING ORDER STATUS
A*************************************************************
A*%%EC
A
DSPSIZ(24 80 *DS3)
A
CHGINPDFT(CS)
A
CA03(15 ′ End′ )
A
PRINT
A
INDARA
A
R CUSHDG
A
OVERLAY
A
1 27′ Check Order Status
′
A
DSPATR(HI)
A
R CUSFTG
A
23 2′ F3=Exit′
A
COLOR(BLU)
A
R CUSPMT
A
OVERLAY
A
3 2′ Type selection, press Enter.′
A
COLOR(BLU)
A
ORD
5A I 5 39DSPATR(PC)
A
DSPATR(HI)
A 99
ERRMSG(′ No orders found,try 0-9′ 99)
A
COLOR(WHT)
A
5 2′ Order number . . . . . . . . . . .′
A
R CUSFLDS
A
OVERLAY
A
3 2′ Customer Name. . . . . . . . . . :′
A
NAME
20A O 3 37
A
5 2′ Order Number . . . . . . . . . . :′
A
ORD
5A O 5 37
A
7 2′ Status . . . . . . . . . . . . . :′
A
STAT
10A O 7 37
A
7 48DATE EDTCDE(Y)
A
21 2′ Press Enter to continue.′
A
COLOR(BLU)
A
A****************************************************************
A*
A* You will have to edit the next statement to your system name.
A* (F11 to scroll right)
A* Make sure you right justify it (leave no blanks in URL).
A*
For example, change --->″http://s1046401.sysland.ibm.comA*
to this ---->
″http://9.5.10.126A*
A****************************************************************
A
23 2HTML(′<IMG SRC=
A
″http://s1046401.sysland.ibm.comA
/QOpenSys/ORDER/IMG/ordstat.gif″ A
align=″right″
> ′)
A
274
Unleashing AS/400 Applications on the Internet
Appendix C. Special Notices
This publication is intended to help those people who are responsible for the task of recommending
and implementing an AS/400 network computing solution. The information in this publication is not
intended as the specification of any programming interfaces that are provided by the products
mentioned in this book. See the PUBLICATIONS section of the IBM Programming Announcement for
more information about what publications are considered to be product documentation.
References in this publication to IBM products, programs or services do not imply that IBM intends to
make these available in all countries in which IBM operates. Any reference to an IBM product,
program, or service is not intended to state or imply that only IBM′s product, program, or service may
be used. Any functionally equivalent program that does not infringe any of IBM′s intellectual property
rights may be used instead of the IBM product, program or service.
Information in this book was developed in conjunction with use of the equipment specified, and is
limited in application to those specific hardware and software products and levels.
IBM may have patents or pending patent applications covering subject matter in this document. The
furnishing of this document does not give you any license to these patents. You can send license
inquiries, in writing, to the IBM Director of Licensing, IBM Corporation, 500 Columbus Avenue,
Thornwood, NY 10594 USA.
Licensees of this program who wish to have information about it for the purpose of enabling: (i) the
exchange of information between independently created programs and other programs (including this
one) and (ii) the mutual use of the information which has been exchanged, should contact IBM
Corporation, Dept. 600A, Mail Drop 1329, Somers, NY 10589 USA.
Such information may be available, subject to appropriate terms and conditions, including in some
cases, payment of a fee.
The information contained in this document has not been submitted to any formal IBM test and is
distributed AS IS. The information about non-IBM (″vendor″) products in this manual has been
supplied by the vendor and IBM assumes no responsibility for its accuracy or completeness. The use
of this information or the implementation of any of these techniques is a customer responsibility and
depends on the customer′s ability to evaluate and integrate them into the customer′s operational
environment. While each item may have been reviewed by IBM for accuracy in a specific situation,
there is no guarantee that the same or similar results will be obtained elsewhere. Customers
attempting to adapt these techniques to their own environments do so at their own risk.
Any performance data contained in this document was determined in a controlled environment, and
therefore, the results that may be obtained in other operating environments may vary significantly.
Users of this document should verify the applicable data for their specific environment.
The following document contains examples of data and reports used in daily business operations. To
illustrate them as completely as possible, the examples contain the names of individuals, companies,
brands, and products. All of these names are fictitious and any similarity to the names and addresses
used by an actual business enterprise is entirely coincidental.
Reference to PTF numbers that have not been released through the normal distribution process does
not imply general availability. The purpose of including these reference numbers is to alert IBM
customers to specific information relative to the implementation of the PTF when it becomes available
to each customer according to the normal IBM PTF distribution process.
The following terms are trademarks of the International Business Machines Corporation in the United
States and/or other countries:
 Copyright IBM Corp. 1997
275
AnyNet
APPN
C/400
COBOL/400
IBM
OS/400
RS/6000
VisualAge
WebExplorer
Application System/400
AS/400
Client Access/400
DB2/400
Integrated Language Environment
RPG/400
SQL/400
WebConnection
The following terms are trademarks of other companies:
C-bus is a trademark of Corollary, Inc.
Java and HotJava are trademarks of Sun Microsystems, Incorporated.
Microsoft, Windows, Windows NT, and the Windows 95 logo are trademarks
or registered trademarks of Microsoft Corporation.
PC Direct is a trademark of Ziff Communications Company and is used
by IBM Corporation under license.
Pentium, MMX, ProShare, LANDesk, and ActionMedia are trademarks or
registered trademarks of Intel Corporation in the U.S. and other
countries.
UNIX is a registered trademark in the United States and other
countries licensed exclusively through X/Open Company Limited.
Other company, product, and service names may be trademarks or
service marks of others.
276
Unleashing AS/400 Applications on the Internet
Appendix D. Related Publications
The publications listed in this section are considered particularly suitable for a more detailed
discussion of the topics covered in this redbook.
D.1 International Technical Support Organization Publications
For information on ordering these ITSO publications see “How to Get ITSO Redbooks” on page 279.
•
Using the Information Super Highway , SG24-2499
•
Cool Title About the AS/400 and Internet , SG24-4815
D.2 Redbooks on CD-ROMs
Redbooks are also available on CD-ROMs. Order a subscription and receive updates 2-4 times a year
at significant savings.
CD-ROM Title
System/390 Redbooks Collection
Networking and Systems Management Redbooks Collection
Transaction Processing and Data Management Redbook
AS/400 Redbooks Collection
RS/6000 Redbooks Collection (HTML, BkMgr)
RS/6000 Redbooks Collection (PostScript)
Application Development Redbooks Collection
Personal Systems Redbooks Collection
Subscription
Number
SBOF-7201
SBOF-7370
SBOF-7240
SBOF-7270
SBOF-7230
SBOF-7205
SBOF-7290
SBOF-7250
Collection Kit
Number
SK2T-2177
SK2T-6022
SK2T-8038
SK2T-2849
SK2T-8040
SK2T-8041
SK2T-8037
SK2T-8042
D.3 Other Publications
These publications are also relevant as further information sources:
•
TCP/IP Configuration & Reference V3R7 , (SC41-3420)
•
TCP/IP Fastpath Setup Version 3 , (SC41-3430)
•
AS/400 Sockets Programming V3R7 , (SC41-4422)
•
AS/400 System API Reference V3R7 , (SC41-4801)
•
AS/400 Integrated File System Introduction V3R7 , (SC41-4711)
•
AS/400 NLS Planning Guide , (GC41-9877)
•
ILE C/400 Programming Guide V3R7 , (SC09-2069)
•
ILE C/400 Programming Reference V3R7 , (SC09-2070)
•
ILE COBOL/400 Programming Guide V3R7 , (SC09-2072)
•
ILE COBOL/400 Programming Reference V3R7 , (SC09-2073)
•
ILE RPG/400 Programming Guide V3R7 , (SC09-2074)
•
ILE RPG/400 Programming Reference V3R7 , (SC09-2077)
•
AS/400 REXX/400 Programmers Guide , (SC24-5553)
•
AS/400 REXX/400 Reference , (SC24-5552)
 Copyright IBM Corp. 1997
277
278
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How to Get ITSO Redbooks
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 Copyright IBM Corp. 1997
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Index
Special Characters
@ character 125
@DTW_ASSIGN 129
@DTW_DELSTR 147
&MESSAGE 136, 138
%DEFINE 122, 129
%ENVVAR 152
%FUNCTION 124, 125
% H T M L 122
%INCLUDE 146
%REPORT 123
% R O W block 134
footer 134
header 134
variable 132
%TABLE 131
< A >
27
< A D D R E S S > 27
< B >
27
< B A S E > 27
< B L O C K Q U O T E > 27
< B O D Y > 27
<BR>
27
< C I T E > 27
< C O D E > 27
<DD>
29
< D I R > 27
<DL>
27
<DT>
27
<EM>
27
< F O R M > 27
<H1>
29
<H2>
29
<H3>
29
<H4>
29
<H5>
29
<H6>
29
< H E A D > 29
<HR>
29
< H T M L > 29
< I >
29
< I M G > 29
< I N P U T > 29
< I S I N D E X > 29
< K B D > 29
<LI>
29
< L I N K > 29
< M E N U > 29
<OL>
29
< O P T I O N > 29
<P>
29
< P R E > 29
< S A M P > 29
 Copyright IBM Corp. 1997
< S E L E C T > 29
< S T R O N G > 29
< T E X T A R E A > 29
< T I T L E > 29
<TT>
29
< U >
29
<UL>
29
< V A R > 29
Numerics
5250 workstation gateway 22
5250/HTML workstation gateway 247
AS/400 model selection 249
communications lines and IOPs 249
workstation gateway configuration 248
workstation gateway memory 249
workstation gateway response time 248
A
activation group
reclaiming 39
Add Relational Database Directory Entry
(ADDRDBDIRE) command 141
adding
relational database directory entry 141
ADDRDBDIRE (Add Relational Database Directory
Entry) command 141
address tag 27
anchors 27
API (application programming interface) 126
application access 10
application programming interface (API) 126
application security 53
AS/400 commercial processing workload 240
relative system performance metric 243
AS/400 HTTP server performance
CGI.bin 242
HTTP 242
Net.Data 242
AS/400 internet application scenario
extranet 5
Internet access 5
internet accessible 5
intranet 5
public internet presence 5
AS/400 Java virtual machine 48
client/server programming model 21
netrexx to create Java applet 49
NetRexxC 50
performance 48
persistent connection 21
sockets connection 21
technology preview 48
283
AS/400 Java virtual machine (continued)
Using Perl to create Java applet 50
VisualAge for Java 52
whitepaper 48
AS/400 legacy programming model 22
AS/400 system facility 10
B
base tag 27
bibliography 277
blockquote tag 27
body tag 27
bold tag 27
built-in function 129
C
C language 11
C + + l a n g u a g e 11
caching 12
caching control 13
caching strategy 13
calling function 125
calling high-level language program 126
CCSID 819 16
CCSIDs and ISO character sets 16
CGI 10
check digit 23
citation tag 27
class browser 12
client/server programming model
persistent connection 21
sockets connection 21
COBOL language 11
code page 15
code tag 27
command, CL
Add Relational Database Directory Entry
(ADDRDBDIRE) 141
ADDRDBDIRE (Add Relational Database Directory
Entry) 141
Copy From Stream File (CPYFRMSTMF) 46
Copy To Stream File (CPYTOSTMF) 46
CPYFRMSTMF (Copy From Stream File) 46
CPYTOSTMF (Copy To Stream File) 46
Create Service Program (CRTSRVPGM) 39
CRTSRVPGM (Create Service Program) 39
RCLACTGRP (Reclaim Activation Group) 39
Reclaim Activation Group (RCLACTGRP) 39
Work with Relational Database Directory Entries
(WRKRDBDIRE) 117
WRKRDBDIRE (Work with Relational Database
Directory Entries) 117
c o m m i t 142
Common Gateway Interface (CGI) 7
communications/LAN IOP 246
conditional logic 147
284
Unleashing AS/400 Applications on the Internet
connections per second 237
connection rate 239
file size 239
WebStone 239
content authoring 11
content management 11
cookie 14
Copy From Stream File (CPYFRMSTMF)
command 46
Copy To Stream File (CPYTOSTMF) command 46
copying
from stream file 46
to stream file 46
counter 128
CPYFRMSTMF (Copy From Stream File)
command 46
CPYTOSTMF 155
CPYTOSTMF (Copy To Stream File) command 46
Create Service Program (CRTSRVPGM) command
creating
service program 39
CRTSRVPGM (Create Service Program) command
D
data source 113
DATABASE 142, 144
database services 10
DB_CASE 144
DB2WWW 246
DDS keyword (″HTML″) 23
DDS specification 23
debug HTTP server 166
debugger 12
default report 153
define section 115, 117
definition list description tag 29
definition list item tag 27
definition list tag 27
different Web models 6
directory list tag 27
distributed web model
applet 8
Java 8
lively animation 8
parameter checking 8
sound 8
DTW_DEFAULT_REPORT 135
DTW_HTML_TABLE 135
DTW_REXX 139
DTW_SYSTEM 144
DTW_TABLE 144
dynamic document 10
E
editor 12
emphasis tag
27
39
39
enterprise distributed web model
environment variable 152
error message
net.data 156
EXEC_PATH 163
9
F
file size 245
file system 244
flat file interface function 131
forms 112
from stream file
copying 46
function
calling 125
flat file interface 131
general 129
m a t h 130
REXX 118
string manipulation 130
table manipulation 130
Web registry 131
word manipulation 130
function call 121
function definition 118, 124
function keys 23
function section 115
G
general function 129
getting net.data up 159
global set 125
H
head tag 29
hidden field 14
how used 15
hidden variables 147
history mechanism 12
horizontal tag 29
how fast can web site go 237
HTML
blocks 122
HTML forms tag 27
HTML section 115, 119, 121
HTML syntax 27
HTML tag 29
HTML3.2 25
HTTP CGI programming model 18
CGI program parameter data 20, 58
connectionless 20, 58
environment variable 19, 57
named activation group 20, 58
performance 20, 58
pre-started server job 20, 58
standard-input 19, 57
HTTP CGI programming model (continued)
Stdin/Stdout 20, 58
I
ILE (integrated language environment) 35
image tag 29
imagemap 30
IN variable 126
INCLUDE_PATH 146, 163
index tag 29
INOUT variable 126
input tag 29
integrated file system 155
integrated file system consideration
application 45
environment 45
flexibility 45
NFS 44
performance 45
QDLS 43
qfilesvr.400 44
QLANSrv 43
QNetWare 44
qopensys 43
QOPT 43
QSYS.LIB 43
root 43
UDFS 44
integrated language environment
*CALLER activation group 37
*NEW activation group 37
*SRVPGM 35
ACTGRP(*CALLER) 39
activation group 39
activation groups 37
bind by copy 35
bind by reference 35
binding directory 38
CRTSRCPF 42
default activation group 39
exception handling 42
modules and programs 35
NAMED activation group 37
procedures 35
program entry procedure (PEP) 38
QRPGLESRC 42
RCLRSC 42
RPG III source 42
RPG IV source 42
scoping 42
static binding 35
static storage 42
system-named activation group (*NEW) 40
user-named activation group 39
integrated language environment (ILE) 35
interactive web model
Common Gateway Interface (CGI) 7
forms, fields, and buttons 7
Index
285
Internet 16
internet application design considerations
Internet application performance 237
Internet client/server programming model
Internet overview 1
history 2
what is Internet 1
Internet programming models 18
internet visual web management tool 11
intranet 16
italics tag 29
5
18
J
Java applet 48
communicating to CGI 21
downloadable Java 9
Java development environment
Java Script 47
N
12
K
keyboard tag
29
L
language
C 11
C++
11
COBOL 11
PERL 11
REXX 11
RPG 11
language environment 139
build language environment
C 114
C + + 114
COBOL 114
DB2 database 114
REXX 114
RPG 114
legacy 10
level 1 heading tag 27
level 2 heading tag 29
level 3 heading tag 29
level 4 heading tag 29
level 5 heading tag 29
level 6 heading tag 29
line break tag 27
link tag 27
list item tag 29
local set 125
LOGIN 142, 144
114
M
macro 10
macro file 116
286
macro language 112, 113
macro language example 145
MACRO_PATH 163
maintaining state 147
mandatory entry 23
mandatory fill 23
mapping hotspots 32
math function 130
memory requirement 244
menu list tag 29
message blocks 136
migrating from DB2 WWW 166
multiple HTML 146
Unleashing AS/400 Applications on the Internet
net.commerce 228
Net.Data 10, 246
built-in function 129
environment variable 151
error message 156
hidden variable 150
implementation 111
initialization file 140, 162
logical section 115
program object 160
table view 132
URL 165
net.data macro file
writing 114
Network Computing 3
AS/400 benefits for the Internet 4
AS/400 system and network computing
network-centric computing 5
new versions of HTTP
HTTP 1.1 228
numeric-only fields 23
O
option tag 29
ordered list tag 29
OUT variable 126
P
paragraph tag 29
PASSWORD 142, 143, 144
PERL language 11
persistent connection 23
pre-formatted text tag 29
predefined variable 151
programming alternatives 17
project manager 12
Q
QTMHHTP1 user profile
139, 143, 164
3
R
U
range checking 23
RCLACTGRP (Reclaim Activation Group)
command 39
Reclaim Activation Group (RCLACTGRP)
command 39
reclaiming
activation group 39
relational database directory 117, 141
relational database directory entries
working with 117
relational database directory entry
adding 141
report blocks 134
reports 112
REXX function 118
REXX language 11
REXX language environment variable 133
REXX program 118
RISC 243
road map 56
RPG language 11
RPG program 127
underline text tag 29
underlined tag 29
unordered list tag 29
user ID 143
user profile
QTMHHTP1 139, 143, 164
using include file 146
S
sample tag 29
select box 154
select tag 29
sending multiple requests 12
service and support 168
service program
creating 39
SHOWSQL 144
simple web model
static web page 6
SQL_CODE 144
status of user request 14
string manipulation function 130
strong emphasis tag 29
synchronization 12
system function macro 145
SYSTEM language environment variable
V
variable 117, 121, 125
variable tag 29
variables 112
visual builder 12
visual web manager 11
VisualAge Java for AS/400
12
W
Web registry function 131
Web serving capacity 242
word manipulation function 130
Work with Relational Database Directory Entries
(WRKRDBDIRE) command 117
working with
relational database directory entries 117
writing net.data macro file 114
WRKRDBDIRE (Work with Relational Database
Directory Entries) command 117
133
T
table manipulation function 130
table variables 131
textarea tag 29
title tag 29
to stream file
copying 46
transaction context 12
TRANSACTION_SCOPE 144
transactions 12
typetype tag 29
Index
287
288
Unleashing AS/400 Applications on the Internet
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